Erectile Dysfunction

Overview

Definition

Erectile dysfunction (ED) is the recurrent failure to achieve or maintain consistent rigid penile erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy for satisfactory sexual intercourse.

Clinical importance:

• Very common, but complex disorder with significant quality Quality Activities and programs intended to assure or improve the quality of care in either a defined medical setting or a program. The concept includes the assessment or evaluation of the quality of care; identification of problems or shortcomings in the delivery of care; designing activities to overcome these deficiencies; and follow-up monitoring to ensure effectiveness of corrective steps. Quality Measurement and Improvement of life implications 
• May be the initial symptom for underlying cardiovascular disease

Epidemiology

Globally, at least 150 million men suffer from ED:

• In the United States, 52% of men between 40 and 70 years of age are affected.
• By 40 years of age, about 40% of men experience ED, whereas, about 70% of men report ED by 70 years of age.

Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency of ED is closely related to increased age and presence of other systemic comorbidities Comorbidities The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival. St. Louis Encephalitis Virus.

Etiology

Erectile dysfunction is a multifactorial disease process with many contributing factors. There are many factors that can be prevented or adjusted to improve the ability to obtain or maintain erections:

• Organic:
  • Peripheral arterial disease (PAD)
  • Aortoiliac occlusive disease 
  • Atherosclerosis Atherosclerosis Atherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient. Atherosclerosis and coronary artery Coronary Artery Truncus Arteriosus disease (CAD) 
  • Sleep apnea Sleep apnea Repeated cessation of breathing for > 10 seconds during sleep and results in sleep interruption, fatigue, and daytime sleepiness. Obstructive Sleep Apnea
  • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus ( DM DM Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus)
  • Liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease 
  • Hyperlipidemia (HLD)
  • Hypogonadism Hypogonadism Hypogonadism is a condition characterized by reduced or no sex hormone production by the testes or ovaries. Hypogonadism can result from primary (hypergonadotropic) or secondary (hypogonadotropic) failure. Symptoms include infertility, increased risk of osteoporosis, erectile dysfunction, decreased libido, and regression (or absence) of secondary sexual characteristics. Hypogonadism
  • Alcohol use disorder Alcohol use disorder Alcohol is one of the most commonly used addictive substances in the world. Alcohol use disorder (AUD) is defined as pathologic consumption of alcohol leading to impaired daily functioning. Acute alcohol intoxication presents with impairment in speech and motor functions and can be managed in most cases with supportive care. Alcohol Use Disorder
  • Stroke
  • Spinal cord injuries Spinal cord injuries Spinal cord injuries are complex injuries that involve damage to the neural tissue within the spinal canal. Spinal cord injuries are commonly the result of trauma. Clinical presentation varies depending on the site of injury and on whether the injury is complete or incomplete. Spinal Cord Injuries
  • Traumatic brain injury Traumatic brain injury A form of acquired brain injury which occurs when a sudden trauma causes damage to the brain. Le Fort Fractures
  • Sickle cell anemia Sickle cell anemia A disease characterized by chronic hemolytic anemia, episodic painful crises, and pathologic involvement of many organs. It is the clinical expression of homozygosity for hemoglobin S. Sickle Cell Disease 
  • CKD CKD Chronic kidney disease (CKD) is kidney impairment that lasts for ≥ 3 months, implying that it is irreversible. Hypertension and diabetes are the most common causes; however, there are a multitude of other etiologies. In the early to moderate stages, CKD is usually asymptomatic and is primarily diagnosed by laboratory abnormalities. Chronic Kidney Disease
  • Genital trauma
  • Peyronie’s disease 
  • Post prostatectomy Prostatectomy Complete or partial surgical removal of the prostate. Three primary approaches are commonly employed: suprapubic – removal through an incision above the pubis and through the urinary bladder; retropubic – as for suprapubic but without entering the urinary bladder; and transurethral (transurethral resection of prostate). Benign Prostatic Hyperplasia 
• Psychogenic:
  • Major depressive disorder Major depressive disorder Major depressive disorder (MDD), commonly called depression, is a unipolar mood disorder characterized by persistent low mood and loss of interest in association with somatic symptoms for a duration of ≥ 2 weeks. Major depressive disorder has the highest lifetime prevalence among all psychiatric disorders. Major Depressive Disorder
  • Generalized anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder disorder
  • Performance anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder 
  • Acute stress disorder Acute stress disorder Acute stress disorder describes stress reactions displayed after an individual has experienced a traumatic event. Symptoms last more than 3 days but less than 1 month and include re-experiencing the event as flashbacks or nightmares, avoidance of reminders of the event, irritability, hyperarousal, and poor memory and concentration. Acute Stress Disorder
• Medications:
  • Beta blockers
  • Antidepressants
  • Antipsychotics
  • Spironolactone Spironolactone A potassium sparing diuretic that acts by antagonism of aldosterone in the distal renal tubules. It is used mainly in the treatment of refractory edema in patients with congestive heart failure, nephrotic syndrome, or hepatic cirrhosis. Its effects on the endocrine system are utilized in the treatments of hirsutism and acne but they can lead to adverse effects. Potassium-sparing Diuretics
  • Ketoconazole Ketoconazole Broad spectrum antifungal agent used for long periods at high doses, especially in immunosuppressed patients. Azoles 
  • Cimetidine Cimetidine A histamine congener, it competitively inhibits histamine binding to histamine h2 receptors. Cimetidine has a range of pharmacological actions. It inhibits gastric acid secretion, as well as pepsin and gastrin output. Antihistamines

Pathophysiology

Anatomy

The penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy is made of cylindrical structures (paired corpus cavernosa and corpus spongiosum Corpus spongiosum Penis: Anatomy):

• Corpus cavernosa:
  • Contained in a collagenous sheath called tunica albuginea Tunica albuginea Penis: Anatomy 
  • Made of sinusoids Sinusoids Liver: Anatomy supported by a fibrous Fibrous Fibrocystic Change skeleton
• Corpus spongiosum Corpus spongiosum Penis: Anatomy:
  • Ventrally located, becoming the glans distally
  • Contains the urethra Urethra A tube that transports urine from the urinary bladder to the outside of the body in both the sexes. It also has a reproductive function in the male by providing a passage for sperm. Urinary Tract: Anatomy, surrounded by sinusoids Sinusoids Liver: Anatomy

Vascular supply to penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy is supplied by the internal iliac artery:

• Internal pudendal artery becomes the common penile artery, which has 3 branches:
  • Cavernosal artery: gives off helicine arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology that supply the corpora cavernosa Corpora cavernosa Penis: Anatomy 
  • Dorsal artery: provides engorgement Engorgement Mastitis of glans 
  • Bulbourethral artery: supplies the corpora spongiosum
• Venous drainage of corporal bodies via emissary veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology:
  • Emissary veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology connect to the deep dorsal vein of the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy. 
  • Rapid drainage of venous blood results in detumescence.

Normal erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy

• Sexual stimuli initiate a downstream cascade of complex neuronal and molecular pathways.
• Neuroanatomic pathway:
  • Reflex mediated by the CNS:
    • Parasympathetic nerve roots S2 S2 Heart Sounds– S4 S4 Heart Sounds 
    • Cholinergic neuronal fibers stimulate the cavernosal endothelial cells to produce NO.
  • NO is the predominant neurotransmitter of erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy synthesized by NO synthase.
    • NO stimulates guanylate cyclase Guanylate cyclase An enzyme that catalyzes the conversion of GTP to 3. Diarrheagenic E. coli (GC) in the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy.
    • GC cleaves guanosine triphosphate (GTP) into cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors.
    • ↑ cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors promotes protein kinase Protein kinase A family of enzymes that catalyze the conversion of ATP and a protein to adp and a phosphoprotein. Interferons G-dependent smooth-muscle relaxation by decreasing intracellular calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes → penile erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy 
  • Phosphodiesterase type 5 degrades cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors and promotes detumescence (flaccid penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy). 
• Erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy is a balance between arterial blood inflow and venous drainage.
  • Penile corpora cavernosal bodies are cylindrical structures that fill with blood during an erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy.
    • Relaxation of sinusoidal smooth muscles Smooth muscles Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. Muscle Tissue: Histology allows for rapid blood filling and expansion. 
    • Venous occlusion restricts blood outflow via compression Compression Blunt Chest Trauma of venules Venules The minute vessels that collect blood from the capillary plexuses and join together to form veins. Veins: Histology beneath the rigid tunica albuginea Tunica albuginea Penis: Anatomy, thereby maintaining penile rigidity Rigidity Continuous involuntary sustained muscle contraction which is often a manifestation of basal ganglia diseases. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Megacolon. 
  • Sinusoids Sinusoids Liver: Anatomy of the corpus spongiosum Corpus spongiosum Penis: Anatomy get engorged, pressurize the urethral lumen, and facilitate forceful ejaculation.

Pathogenesis

• Neurogenic:
  • Intact nervous system Nervous system The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). It is divided according to its anatomical components as well as its functional characteristics. The brain and spinal cord are referred to as the central nervous system, and the branches of nerves from these structures are referred to as the peripheral nervous system. Nervous System: Anatomy, Structure, and Classification is a key component for initiation of erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy
  • Any neurological compromise can inhibit the ability to achieve an erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy:
    • Peripheral nerve damage (e.g., penile surgery) 
    • Central nerve damage (e.g., spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy injury, multiple sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor) 
    • Impaired contractility of cavernosal smooth muscle (seen in defects in neurotransmitters, including NO and cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors)
• Psychogenic:
  • Decreased sexual desire or stimulation will cause difficulty in achieving an erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy. 
  • Generalized or performance-related anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder, depression, and stress can cause ED.
• Vascular:
  • Vascular compromise with arterial insufficiency or venous leak can impair blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure to the erectogenic tissue.
  • Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus, HLD, smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases, and cardiovascular disease can affect local (and systemic) vasculature.
• Hormonal:
  • Low testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens levels can affect erectile mechanism, but the exact level corresponding to ED is not known.
  • Others: thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy and adrenal disorders

Clinical Presentation and Diagnosis

Initial encounter

• Men of any age complaining of a recurrent inability to sustain an erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy rigid enough for sexual activity 
• ED is a very sensitive topic and patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may not present with this condition as their main complaint.
• Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may initially present with vague complaints about their sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria life or depression.

Diagnosis

Majority of cases are diagnosed based on history and physical examination.

Comprehensive medical and sexual history:

• Marital or relationship issues 
• Performance anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder 
• Validated International Index of Erectile Function (IIEF) is a 15-question scale Scale Dermatologic Examination, assessing the following 5 domains of male sexual activity:
  • Sexual desire 
  • Erectile function 
  • Intercourse satisfaction 
  • Orgasmic function 
  • Overall sexual satisfaction 
• Depression 
• Assess for lifestyle factors:
  • Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases 
  • Alcohol use 
  • Illicit drug use 
• Relevant medical and surgical history
  • Any prior genitourinary surgeries 
  • CAD
  • DM DM Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus
  • PAD
  • HLD
• ED history:
  • Is the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy hard enough for penetrative sexual activity?
  • Do you wake up in the morning with an erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy? 
  • Any history of premature Premature Childbirth before 37 weeks of pregnancy (259 days from the first day of the mother’s last menstrual period, or 245 days after fertilization). Necrotizing Enterocolitis ejaculation?
  • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with sexual activity?

Physical examination:

• Obtain resting vital signs.
• Measure waist circumference Waist circumference Measure of abdominal obesity and is associated with increased cardiovascular risks. Obesity and BMI BMI An indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese). Obesity. 
• Observe the chest for gynecomastia Gynecomastia Gynecomastia is a benign proliferation of male breast glandular ductal tissue, usually bilateral, caused by increased estrogen activity, decreased testosterone activity, or medications. The condition is common and physiological in neonates, adolescent boys, and elderly men. Gynecomastia.
• Palpate peripheral pulse. 
• General genitourinary exam:
  • Scrotal exam with assessment of testicle size, consistency Consistency Dermatologic Examination, and location 
  • Penile exam to assess for lesions, plaques, or any anomalies

Laboratory tests:

• Early morning total testosterone Testosterone A potent androgenic steroid and major product secreted by the leydig cells of the testis. Its production is stimulated by luteinizing hormone from the pituitary gland. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to dihydrotestosterone or estradiol. Androgens and Antiandrogens levels to establish baseline 
• Hemoglobin and hematocrit Hematocrit The volume of packed red blood cells in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, anemia shows a low value; polycythemia, a high value. Neonatal Polycythemia to rule out anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types 
• Hemoglobin A1C Hemoglobin A1c Products of non-enzymatic reactions between glucose and hemoglobin a, occurring as a minor fraction of the hemoglobin components of human erythrocytes. Hemoglobin a1c is hemoglobin a with glucose covalently bound to the terminal valine of the beta chain. Glycated hemoglobin a is used as an index of the average blood sugar level over a lifetime of erythrocytes. Diabetes Mellitus to determine glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance status 
• Comprehensive metabolic panel Comprehensive metabolic panel Primary vs Secondary Headaches
• Lipid profile Lipid profile Lipid Disorders

Ancillary diagnostic tests Diagnostic tests Diagnostic tests are important aspects in making a diagnosis. Some of the most important epidemiological values of diagnostic tests include sensitivity and specificity, false positives and false negatives, positive and negative predictive values, likelihood ratios, and pre-test and post-test probabilities. Epidemiological Values of Diagnostic Tests:

• Simple “stamp” test:
  • Wrap a ring of stamps around the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy and assess if the stamp breaks in the morning. 
  • Positive erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy = broken stamp 
• Office intracavernous injection (ICI) with prostaglandin (PG) E1 E1 An aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone, a major mammalian estrogen. It is converted from androstenedione directly, or from testosterone via estradiol. In humans, it is produced primarily by the cyclic ovaries, placenta, and the adipose tissue of men and postmenopausal women. Noncontraceptive Estrogen and Progestins (erectogenic agent) into the corpora cavernosa Corpora cavernosa Penis: Anatomy of the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy:
  • PGE1 produces vasodilation Vasodilation The physiological widening of blood vessels by relaxing the underlying vascular smooth muscle. Pulmonary Hypertension Drugs.
  • Assesses for erectile response and the ability to maintain an erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy 
• Penile duplex Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) ultrasound:
  • Used to identify possible veno-occlusive dysfunction or arterial insufficiency 
  • Performed after ICI to stimulate an erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy
• Invasive vascular testing, such as pudendal angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery, is rarely used and only indicated for severe vascular disruption arising from pelvic trauma.

Management

Treatment approach

• Holistic approach to address the underlying cause:
  • Medical condition-related ED
  • Anatomical or surgical correction of factors leading to ED 
  • Psychogenic factors
• Proceed from least to maximally invasive options as needed.
• There are 2 individuals to keep in mind: patient and partner

Medical treatment

• Lifestyle modifications:
  • Reduce cardiac risk factors.
  • Adjust anti-hypertensive drug doses as indicated. 
  • Optimize diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus care. 
  • Decrease alcohol use. 
  • Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases cessation 
  • Weight loss Weight loss Decrease in existing body weight. Bariatric Surgery 
  • Diet low in saturated fats Fats The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (dietary fats) as a source of energy. Energy Homeostasis 
  • Increase physical exercise. 
• Vacuum erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy device: 
  • Mechanical pump Pump ACES and RUSH: Resuscitation Ultrasound Protocols used to generate negative pressure around the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy and sustain erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy 
  • Causes dilation of the cavernous spaces of the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy 
  • Erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy maintained with a constrictive ring/band placed at the base of the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy 
  • Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation:
    • Men on long-term anticoagulants Anticoagulants Anticoagulants are drugs that retard or interrupt the coagulation cascade. The primary classes of available anticoagulants include heparins, vitamin K-dependent antagonists (e.g., warfarin), direct thrombin inhibitors, and factor Xa inhibitors. Anticoagulants are at increased risk of bleeding or bruising. 
    • Unexplained priapism Priapism A prolonged painful erection that may lasts hours and is not associated with sexual activity. It is seen in patients with sickle cell anemia, advanced malignancy, spinal trauma; and certain drug treatments. Penile Anomalies and Conditions
  • Adverse reactions:
    • Hematoma Hematoma A collection of blood outside the blood vessels. Hematoma can be localized in an organ, space, or tissue. Intussusception if over-pressurized 
    • Ecchymosis Ecchymosis Extravasation of blood into the skin, resulting in a nonelevated, rounded or irregular, blue or purplish patch, larger than a petechia. Orbital Fractures if constrictive band left on for too long 
• Phosphodiesterase-5 (PDE-5) inhibitors: 
  • Sildenafil Sildenafil A phosphodiesterase type-5 inhibitor; vasodilator agent and urological agent that is used in the treatment of erectile dysfunction and primary pulmonary hypertension. Phosphodiesterase Inhibitors, vardenafil Vardenafil A piperazine derivative, phosphodiesterase 5 inhibitor and vasodilator agent that is used as a urological agent in the treatment of erectile dysfunction. Phosphodiesterase Inhibitors, tadalafil Tadalafil A carboline derivative and phosphodiesterase 5 inhibitor that is used primarily to treat erectile dysfunction; benign prostatic hyperplasia and primary pulmonary hypertension. Phosphodiesterase Inhibitors
  • Oral medications that promote increased levels of cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors in the penile vasculature
  • To be taken before planned sexual activity and must involve sexual stimulation 
  • Contraindicated in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship taking nitrates Nitrates Nitrates are a class of medications that cause systemic vasodilation (veins > arteries) by smooth muscle relaxation. Nitrates are primarily indicated for the treatment of angina, where preferential venodilation causes pooling of blood, decreased preload, and ultimately decreased myocardial O2 demand. Nitrates, as it may cause an unsafe drop in BP
  • Adverse reactions:
    • Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess 
    • Flushing 
    • Heartburn Heartburn Substernal pain or burning sensation, usually associated with regurgitation of gastric juice into the esophagus. Gastroesophageal Reflux Disease (GERD) 
    • Nasal congestion 
    • Visual changes 
    • Rarely may cause priapism Priapism A prolonged painful erection that may lasts hours and is not associated with sexual activity. It is seen in patients with sickle cell anemia, advanced malignancy, spinal trauma; and certain drug treatments. Penile Anomalies and Conditions ( erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy lasting > 4 hours) 
• Intra-urethral suppository: 
  • PGE1 ( alprostadil Alprostadil Coarctation of the Aorta) suppository:
    • Also known as Medicated Urethral System for Erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy (MUSE)
    • Administered via urethral meatus 
    • Dissolves into the corpus spongiosum Corpus spongiosum Penis: Anatomy and increases cAMP cAMP An adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth. Phosphodiesterase Inhibitors levels in smooth muscles Smooth muscles Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. Muscle Tissue: Histology 
    • Leads to corporal smooth-muscle relaxation and erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy 
  • Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation:
    • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with urethral stricture Stricture Primary Sclerosing Cholangitis disease, hypospadias Hypospadias A birth defect due to malformation of the urethra in which the urethral opening is below its normal location. In the male, the malformed urethra generally opens on the ventral surface of the penis or on the perineum. In the female, the malformed urethral opening is in the vagina. Penile Anomalies and Conditions, urethritis Urethritis Inflammation involving the urethra. Similar to cystitis, clinical symptoms range from vague discomfort to painful urination (dysuria), urethral discharge, or both. Urinary Tract Infections (UTIs) 
    • Sickle cell disease Sickle cell disease Sickle cell disease (SCD) is a group of genetic disorders in which an abnormal Hb molecule (HbS) transforms RBCs into sickle-shaped cells, resulting in chronic anemia, vasoocclusive episodes, pain, and organ damage. Sickle Cell Disease or hematological disorders 
    • Not to be used with a pregnant partner, as it may induce labor
  • Adverse reactions:
    • Penile pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways 
    • Urethral burning or irritation 
    • Priapism Priapism A prolonged painful erection that may lasts hours and is not associated with sexual activity. It is seen in patients with sickle cell anemia, advanced malignancy, spinal trauma; and certain drug treatments. Penile Anomalies and Conditions possible, but rare
• ICI therapy:
  • Direct PGE1, papaverine, phentolamine Phentolamine A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of raynaud disease and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease. Antiadrenergic Drugs combination administered as a penile injection into the corpora cavernosa Corpora cavernosa Penis: Anatomy:
    • PGE1 increases cAMP cAMP An adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth. Phosphodiesterase Inhibitors levels in the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy. 
    • Papaverine is a non-specific PDE inhibitor that increases cAMP cAMP An adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth. Phosphodiesterase Inhibitors and cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors levels.
    • Phentolamine Phentolamine A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of raynaud disease and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease. Antiadrenergic Drugs is an alpha-1 adrenergic blocker that reduces sympathetic tone in the penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy. 
  • Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation:
    • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship unable to tolerate penile injections 
    • Hematological disorders, increased risk of bleeding 
    • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship taking monoamine oxidase Oxidase Neisseria inhibitors may experience hypertensive crisis Hypertensive Crisis Oxazolidinones. 
  • Adverse reactions:
    • Penile pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways 
    • Bruising 
    • Hematoma Hematoma A collection of blood outside the blood vessels. Hematoma can be localized in an organ, space, or tissue. Intussusception 
    • Priapism Priapism A prolonged painful erection that may lasts hours and is not associated with sexual activity. It is seen in patients with sickle cell anemia, advanced malignancy, spinal trauma; and certain drug treatments. Penile Anomalies and Conditions
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship should not increase the dose without approval, and must proceed to emergency for reversal therapy if the erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy persists > 4 hours ( priapism Priapism A prolonged painful erection that may lasts hours and is not associated with sexual activity. It is seen in patients with sickle cell anemia, advanced malignancy, spinal trauma; and certain drug treatments. Penile Anomalies and Conditions)

Surgical treatment

• Must 1st undergo comprehensive diagnosis and medical management 
• Indicated for failed non-surgical management 
• Obtain cardiac and medical clearance for safe sexual activity:
  • Ability to undergo general anesthesia General anesthesia Procedure in which patients are induced into an unconscious state through use of various medications so that they do not feel pain during surgery. Anesthesiology: History and Basic Concepts and surgery 
  • Establishment of baseline performance status
• Penile implants (2 broad categories)
  • Non-inflatable:
    • Malleable or semi-rigid 
    • 2 flexible rods inserted into each corporal body 
    • Not associated with a pump Pump ACES and RUSH: Resuscitation Ultrasound Protocols device 
    • Can be manipulated (straight or bent position)
    • There is no flaccid state upon implantation Implantation Endometrial implantation of embryo, mammalian at the blastocyst stage. Fertilization and First Week. 
  • 3-piece inflatable implant:
    • Allows for flaccid and erect states 
    • Fluid from the intraabdominal reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli connects to tubing to the pump Pump ACES and RUSH: Resuscitation Ultrasound Protocols in the scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy. 
    • Pump Pump ACES and RUSH: Resuscitation Ultrasound Protocols in the scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy is activated by the patient to inflate the penile cylinders inserted into the corpora cavernosa Corpora cavernosa Penis: Anatomy. 
• Complications:
  • Associated with infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease, as these implants are foreign bodies (usually requires the removal of device and treatment with antibiotics) 
  • Device malfunction 
  • Urethral injury during insertion of the implant 
  • Device crossover, where penile cylinder may encroach on the contralateral side 
  • Penile or scrotal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways due to device placement

Clinical Relevance

• Peyronie’s disease: a condition caused by a fibrous-tissue disorder of the tunica albuginea Tunica albuginea Penis: Anatomy that results in penile deformity Deformity Examination of the Upper Limbs, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, and ED. Diagnosis is based on history and physical examination. Ultrasound can help define the fibrotic tissue. Medical treatments include intralesional collagenase Clostridium histolyticum Clostridium histolyticum A species of gram-positive, strongly proteolytic bacteria in the family clostridiaceae. It contains several forms of collagenase whose action can lead to gas gangrene in humans and horses. Gas Gangrene (breaks up fibrous Fibrous Fibrocystic Change substances), verapamil Verapamil A calcium channel blocker that is a class IV anti-arrhythmia agent. Pulmonary Hypertension Drugs, or interferon alpha-2b injection. Surgical therapy (e.g., plication, grafting, or penile prosthesis) is an option for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship refractory to medical therapy.
• Hypogonadism Hypogonadism Hypogonadism is a condition characterized by reduced or no sex hormone production by the testes or ovaries. Hypogonadism can result from primary (hypergonadotropic) or secondary (hypogonadotropic) failure. Symptoms include infertility, increased risk of osteoporosis, erectile dysfunction, decreased libido, and regression (or absence) of secondary sexual characteristics. Hypogonadism: a condition characterized by the decreased production of sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors in the gonads Gonads The gamete-producing glands, ovary or testis. Hormones: Overview and Types. In men, hypogonadism Hypogonadism Hypogonadism is a condition characterized by reduced or no sex hormone production by the testes or ovaries. Hypogonadism can result from primary (hypergonadotropic) or secondary (hypogonadotropic) failure. Symptoms include infertility, increased risk of osteoporosis, erectile dysfunction, decreased libido, and regression (or absence) of secondary sexual characteristics. Hypogonadism can result from primary or secondary testicular failure due to pituitary Pituitary A small, unpaired gland situated in the sella turcica. It is connected to the hypothalamus by a short stalk which is called the infundibulum. Hormones: Overview and Types or hypothalamic disorders. Symptoms of hypogonadism Hypogonadism Hypogonadism is a condition characterized by reduced or no sex hormone production by the testes or ovaries. Hypogonadism can result from primary (hypergonadotropic) or secondary (hypogonadotropic) failure. Symptoms include infertility, increased risk of osteoporosis, erectile dysfunction, decreased libido, and regression (or absence) of secondary sexual characteristics. Hypogonadism include ED, decreased libido, and regression Regression Corneal Abrasions, Erosion, and Ulcers, or absence of secondary sexual characteristics Secondary Sexual Characteristics Precocious Puberty.
• DM DM Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus: a heterogeneous group of metabolic diseases characterized by chronic hyperglycemia Hyperglycemia Abnormally high blood glucose level. Diabetes Mellitus. Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus leads to various complications including ED. Poor glycemic control, long duration of diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus, and the presence of microvascular and cardiovascular diseases correlate with the severity of ED. 
• Prostate-cancer treatment: Prostate Prostate The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid. cancer is a slow-growing malignancy Malignancy Hemothorax affecting the prostate Prostate The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid. gland. Treatment options include radiotherapy and radical prostatectomy Radical Prostatectomy Prostate Cancer, both of which are commonly complicated in individuals with ED. Effects of treatments can temporarily or permanently damage the nervous and vascular structures integral for erection Erection The state of the penis when the erectile tissue becomes filled or swollen (tumid) with blood and causes the penis to become rigid and elevated. It is a complex process involving central nervous system; peripheral nervous systems; hormones; smooth muscles; and vascular functions. Penis: Anatomy. Nerve-sparing surgery is performed when indicated for better erectile function postoperatively. Medications for ED are also generally effective in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship scheduled for the treatment of prostate Prostate The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid. cancer.