Erectile Dysfunction – Causes, Symptoms, Diagnosis, Treatment and Ongoing care



  • Inability to achieve or maintain an erection sufficient for satisfactory sexual performance (1)[C]
  • Erectile dysfunction is sometimes assumed to be a symptom of the aging process in men, but it can likely result from concurrent medical conditions of the patient or from medications that patients may be taking to treat those conditions.
  • Normal penile erection requires full functioning of the vascular, nervous, and hormonal systems.
  • System(s) affected: Cardiovascular; Nervous; Urologic; Reproductive
  • Synonym: Impotence



  • Overall prevalence for erectile dysfunction per the Massachusetts Male Aging Study (2):
    • 52% in men age 40–70 years
    • Age-related increase ranging from 12.4% in men age 40–49 years up to 46.6% in men age 50–69 years
  • A study of US health professionals found prevalence of sexual dysfunction 12% in men <59 years old, 22% age 60–69 years, and 30% >69 years old (3).

Risk Factors

  • Age
  • Cardiovascular disease
  • Diabetes
  • Metabolic syndrome
  • Lower urinary tract systems of benign prostatic hyperplasia
  • Medications that induce erectile dysfunction
  • Urologic surgery or trauma/injury to pelvic area or spinal cord
  • Central neurologic and endocrinologic conditions
  • Substance abuse
  • Psychological conditions: stress, anxiety, or depression
  • Smoking


Rarely related to chromosomal disorders


  • Erectile dysfunction may result from problems with systems required for normal penile erection:
    • Vascular: Diseases that compromise blood flow:
      • Peripheral vascular disease, arteriosclerosis, essential hypertension
    • Neurologic: Diseases that impair nerve conduction to brain or penile vasculature:
      • Spinal cord injury, trauma (bicycling accident), stroke, diabetes
    • Endocrine: Diseases associated with changes in testosterone, luteinizing hormone, prolactin levels
    • Psychological: Patients suffering from malaise, depression, performance anxiety, or Alzheimer’s disease
  • Social habits such as smoking or excessive alcohol intake
  • Medications may cause erectile dysfunction.
  • Structural injury or trauma

Geriatric Considerations

Aging alone is not a cause.

Commonly Associated Conditions

  • Cardiovascular disease
    • Men with erectile dysfunction have a greater likelihood of having angina, myocardial infarction, stroke, transient ischemic attack, congestive heart failure, or cardiac arrhythmia compared to men without erectile dysfunction (3).
  • Diabetes
  • Psychiatric disorders

Erectile dysfunction, Erection, Cardiovascular disease, Peyronie's disease, Peyronie, benign prostatic hyperplasia, penile erection, peripheral vascular disease, essential hypertension, stress anxiety, spinal cord injury, luteinizing hormone,


  • Inability to maintain erection satisfactory for intercourse
  • Inability to achieve erection
  • Reduced body hair
  • Thyromegaly
  • Gynecomastia
  • Testicular atrophy or absence
  • Deformed penis
  • Peripheral vascular disease
  • Neuropathy


  • Identify concurrent medical illnesses or surgical procedures
  • Social history: Smoking, ethanol intake, recreational drug use
  • List of prescription and nonprescription medications

Physical Exam

  • Assess vital signs (blood pressure and heart rate)
  • Signs and symptoms of hypogonadism: Gynecomastia, small testicles, decreased body hair
  • Abnormal penile curvature (Peyronie’s disease)
  • Assess for central obesity, thyroid goiter
  • Detailed examination of the cardiovascular, neurologic, and genitourinary systems
    • Check femoral and lower extremity pulses to assess vascular supply to genitals
    • Check anal sphincter tone and genital reflexes for adequate nerve supply
    • Digital rectal exam for patients age >50 years to rule out benign prostatic hyperplasia (BPH)
  • Screen for cardiovascular risk factors

Diagnostic Tests & Interpretation

  • Nocturnal penile tumescence and rigidity assessment
  • Consider the following only in rare circumstances, when indicated:
    • 24-hour urine zinc
    • Dorsal nerve somatosensory-evoked potentials
    • Sacral evoked response
    • Penile–brachial blood pressure (BP)
    • Aortogram
    • Selective pudendal angiogram
    • Dynamic cavernosography
    • Penile BP
  • Optional diagnostic tests: psychological or psychiatric evaluation


Initial lab tests

  • Fasting serum glucose
  • Lipid profile
  • Serum testosterone levels drawn in the morning (2 serial levels are needed to confirm hypogonadism)
  • Thyroid-stimulating hormone
  • Prolactin


Doppler, angiogram, cavernosogram

Diagnostic Procedures/Surgery

International Index of Erectile Function (IIEF) Survey may be used to assess the severity of a patient’s erectile dysfunction. The survey is also available in an abbreviated form (IIEF-5).

Differential Diagnosis

  • Endocrine:
    • Thyroid dysfunction
    • Low testosterone
    • High prolactin
    • Diabetes
    • High estrogen effect
    • Renal failure
    • Zinc deficiency
  • Neurologic: Central, Spinal, Peripheral
  • Vascular: Arterial insufficiency, Cavernosal insufficiency, Venous insufficiency
  • Medication: β-blockers, thiazides, antidepressants
  • Psychological: Depression, Schizophrenia, Relationship disorders, Personality disorders, Anxiety
  • Structural:
    • Microphallus, Chordee and Peyronie’s disease, Cavernosal scarring
    • Phimosis, Hypospadias
  • Postsurgical sequelae


Use least invasive therapy first; reserve more invasive therapies for nonresponders.


First Line

Phosphodiesterase type 5 (PDE-5) inhibitors are effective in the treatment of erectile dysfunction associated with diabetes mellitus and spinal cord injury, and sexual dysfunction associated with antidepressants (3).

  • Sildenafil (Viagra): Usual daily dose: 25–100 mg within 30–60 min of sexual intercourse on an empty stomach, at least 2 hours before meals. Duration up to 4 hours.
  • Vardenafil (Levitra): Usual daily dose 5–20 mg within 30–60 minutes of sexual intercourse on an empty stomach, at least 2 hours before meals. Duration up to 4 hours.
  • Tadalafil (Cialis): Usual daily dose 5–20 mg, 2 hours before intercourse. May take without regard to meals. Duration up to 36 hours.

Geriatric Considerations

  • Use doses at the lower end of the dosing range for elderly patients:
    • Sildenafil 25 mg daily
    • Vardenafil 5 mg daily
  • Adverse effects of PDE-5 inhibitors: Headache, facial flushing, dyspepsia, nasal congestion, dizziness, hypotension, increased sensitivity to light (sildenafil and vardenafil), vision changes, lower back pain (tadalafil), and priapism (with excessive doses)

Second Line

  • Penile injectables:
    • Alprostadil, also known as prostaglandin E1, causes smooth muscle relaxation of the arterial blood vessels and sinusoidal tissues in the corpora. Available in 2 formulations:
      • Alprostadil (Caverject): Usual dose: 10–20 mcg, with max dose of 60 mcg. Injection should be made at right angles into one of the lateral surfaces of the proximal third of the penis using a 0.5-inch 27- or 30-gauge needle. Do not use >3 times a week or > once in 24 hours. Patient to notify physician if erection lasts >4 hours for immediate attention. Apply manual pressure at site of injection to prevent hematoma formation. Use with caution in patients with sickle cell disease: Initial trial dose should be administered under supervision of a physician
      • Alprostadil may also be combined with papaverine (Bimix) plus phentolamine(Tri-Mix).
      • Alprostadil (Muse) urethral suppository: 125-, 250-, 500-, and 1,000-mcg pellets. Administer 5–50 minutes before intercourse. No more than 2 doses in 24 hours are recommended.
  • Miscellaneous:
    • Testosterone replacement regimens for patients with primary or secondary hypogonadism as confirmed by decreased libido and low testosterone concentrations.
      • Testosterone patch (Testoderm) 4 mg/patch, 6 mg/patch: Apply 4–6 mg/day to scrotum
      • Testosterone patch (Testoderm TTS) 4 mg/patch, 6 mg/patch: Apply 4–6 mg/day to arm, buttock, back
      • Testosterone patch (Androderm) 2.5 mg/patch: Apply 2.5–5 mg/day to arm, back, abdomen, thigh
      • Testosterone gel (AndroGel 1%) 5 g/packet, 10 g/packet: Apply 5–10 g/day to shoulders, upper arms, abdomen
      • Testosterone cypionate (Depo-Testosterone) 100 mg/mL, 200 mg/mL
      • Testosterone enanthate (Delatestryl) 100 mg/mL, 200 mg/mL: Inject 200–400 mg intramuscularly every 2–4 weeks
    • Contraindications:
      • Avoid injections in patients with bleeding disorders, sickle cell disease or trait, and penile deformities.
      • Avoid use in patients with known allergies to constituents.
      • Nitroglycerin (or other nitrates) and phosphodiesterase inhibitors: Potential for severe, potentially fatal hypotension
    • Precautions:
      • Testosterone: Urinary retention, acne, sodium retention, and gynecomastia
      • Injection therapy: Priapism, fibrosis, hypotension, and nausea
      • Urethral suppositories: Penile pain and irritation, as well as testicular pain
      • Sildenafil: Hypotension (caution for patients on nitrates)
      • PDE-5 inhibitors: Use caution with congenital prolonged QT syndrome, class Ia or II antiarrhythmics, nitroglycerin, α-blockers (e.g., terazosin, tamsulosin), retinal disease, unstable cardiac disease, liver and renal failure
    • Significant possible interactions:
      • PDE-5 inhibitor concentration is affected by CYP3A4 inhibitors (e.g., erythromycin, indinavir, ketoconazole, ritonavir, amiodarone, cimetidine, clarithromycin, delavirdine, diltiazem, fluoxetine, fluvoxamine, grapefruit juice, itraconazole, nefazodone, nevirapine, ritonavir, saquinavir, and verapamil). Serum concentrations and/or toxicity may be increased. Lower starting doses should be used in these patients.
      • PDE-5 inhibitor concentration may be reduced by rifampin and phenytoin.

Additional Treatment

General Measures

  • Penile prosthesis should be reserved for patients who have failed 1st- or 2nd-line therapies.
  • Psychotherapy alone or in combination with psychoactive drugs may be helpful in men whose erectile dysfunction is caused by depression or anxiety.
  • Weight loss and increased physical activity for obese men with erectile dysfunction.
  • Improve partner communication.
  • Reduce performance pressure.
  • Try vacuum erectile device or oral therapy (can be used in conjunction with intracavernous injections). Do not use vacuum devices in men with sickle cell anemia or blood dyscrasias, or those on anticoagulants.
  • Use of psychiatrists, psychologists, sex therapists, vascular surgeons, urologists, endocrinologists, neurologists, or plastic surgeons is often necessary for refractory cases.

Complementary and Alternative Medicine

Yohimbine and herbal therapies are not recommended for the treatment of erectile dysfunction (1).

Surgery/Other Procedures

Penile prosthesis is the most invasive treatment of erectile dysfunction and is reserved for patients who do not respond or are not candidates for oral or injectable therapies. Penile arterial reconstructive surgery is controversial.

Ongoing Care

Follow-Up Recommendations

Patient Monitoring

Treatment should be assessed at baseline and after the patient has completed at least 1–3 weeks of a specific treatment: Monitor the quality and quantity of penile erections and Monitor the level of satisfaction patient achieves.


Diet and exercise recommended to achieve a normal body mass index; limit alcohol


  • All commercially available PDE-5 inhibitors are equally effective. In the presence of sexual stimulation, sildenafil produces satisfactory erections in 56–82% of patients. Similar results are seen in 65–80% of patients taking vardenafil and 62–77% in patients taking tadalafil:
    • Lower success rates with diabetes mellitus or who have postoperative nerve damage.
  • Overall effectiveness is 70–90% for intracavernosal alprostadil and 43–60% for intraurethral alprostadil (4,5).
  • Penile prostheses are associated with a 90% patient satisfaction rate, and the surgical success rate after insertion is 82–98% (4).


1. Montague DK, Jarrow JP, Broderick GA, Dmochowski RR, Heaton JP, Lue TF, et al. The Management of Erectile Dysfunction: An Update. Linthicum, MD: American Urological Association, 2006.

2. Johannes CB, Aranjo AB, Feldman HA, et al. Incidence of erectile dysfunction in men 40–69 years old: Longitudinal results from the Massachusetts Male Aging Study. J Urol. 2000;163:460–3.

3. Heidelbaugh JJ et al. Management of erectile dysfunction. Am Fam Physician. 2010;81:305–12.

4. Lue TF. Erectile dysfunction. N Engl J Med. 2000;342:1802–13.

5. McVary KT. Clinical practice. Erectile dysfunction. N Engl J Med.2007;357:2472–81.



  • 302.72 Psychosexual dysfunction with inhibited sexual excitement
  • 607.84 Impotence of organic origin


  • 398175007 Male erectile disorder (disorder)
  • 198036002 Impotence of organic origin (disorder)

Clinical Pearls

  • Nitrates should be withheld for 24 hours after sildenafil or vardenafil administration and for 48 hours after use of tadalafil.
  • Reserve surgical treatment for patients who do not respond to drug treatment.
  • The use of PDE-5 inhibitors with alpha-adrenergic antagonists may increase the risk of hypotension. Tamsulosin is the least likely to cause orthostatic hypotension.
  • Consult a cardiologist for use of PDE-5 inhibitors in patients with left ventricular dysfunction or NYHA class II. Do not use in patients with NYHA class III or IV.

Jean-Paul Marat

Many tips are based on recent research, while others were known in ancient times. But they have all been proven to be effective. So keep this website close at hand and make the advice it offers a part of your daily life.

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