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Erectile Dysfunction (Impotence)

What Is Erectile Dysfunction?

Erectile dysfunction, commonly known as impotence, is the inability to achieve or maintain an erection adequate for satisfactory sexual performance. It may occur at any age but becomes increasingly frequent as men grow older.

The mechanisms for erection are fairly complex: A sensory stimulus triggers the brain to send nerve impulses down through the spinal cord. These signals trigger the release of a chemical messenger that causes the vessels supplying blood to the penis to dilate. The rod-shaped spongy tissues (corpora cavernosa) in the penis then fill with blood and expand, pressing against the veins that normally allow blood to drain from the penis, thus producing an erection. Interference with any part of this process—whether psychological or physiological—may cause erectile dysfunction. Although an occasional inability to maintain an erection is common and not a sign of a chronic problem, a doctor should be consulted if erectile dysfunction persists. Treatment depends upon the underlying cause.

Who Gets Erectile Dysfunction?

The term “erectile dysfunction” can mean the inability to achieve erection, an inconsistent ability to do so, achieving only partial firmness, or the ability to achieve only brief erections. These various definitions make estimating the incidence of erectile dysfunction difficult.

According to the National Institutes of Health, an estimated 30 million men in the United States experience chronic erectile dysfunction and incidence of the disorder increases with age. Chronic erectile dysfunction affects about 4% of men in their 50s, nearly 17% of men in their 60s, and about 47% of men over the age of 75. Transient erectile dysfunction and inadequate erection affect as many as 50% of men between the ages of 40 and 70.

Diseases (e.g., diabetes, kidney disease, alcoholism, atherosclerosis) account for as many as 70% of chronic erectile dysfunction cases and psychological factors (e.g., stress, anxiety, depression) may account for 10% to 20% of cases. Between 35% and 50% of men with diabetes experience erectile dysfunction.


  • Inability to achieve or maintain an erection sufficient for satisfactory sexual performance.

Causes/Risk Factors

  • Emotional and psychological difficulties such as guilt or anxiety (especially performance anxiety, in which fear of not having an erection becomes so distracting that it becomes a self-fulfilling prophecy).

  • Conditions that affect the brain and decrease the libido (sex drive), including depression or schizophrenia; use of drugs that act on the central nervous system (sedatives, antidepressants, some antihypertensives, antipsychotics, and alcohol); and chronic illnesses such as heart, lung, kidney, or liver disease, and certain types of cancer.

  • Hormonal disturbances that decrease the libido, including diminished testosterone levels, elevated prolactin (due to a pituitary tumor), and hyper- or hypothyroidism.

  • Brain disorders (that do not affect libido but have neurological consequences that affect sexual functioning), including brain tumor and stroke.

  • Spinal cord disorders, such as multiple sclerosis or spinal cord trauma.

  • Damage to the peripheral nerves due to diabetes mellitus or pelvic surgery for disorders such as prostate cancer or rectal cancer.

  • Medications that can sometimes cause sexual dysfunction, including anticholinergics, antihistamines, beta-blockers (and other kinds of antihypertensives), and long-term use of nicotine.

  • Peripheral vascular disease (impaired blood flow to the extremities and the penis).

  • Fatigue.

  • Advancing age.

What If You Do Nothing?

Frequent or chronic erectile problems are unlikely to improve without some form of intervention, particularly among men over the age of 50. There are now proven treatments for erectile dysfunction, but out of embarrassment and/or a lack of knowledge about medical solutions, many men choose to do nothing about their problem, which often leads to emotional distress.


  • A medical examination may indicate neurological, vascular, or hormonal disease, or Peyronie's disease (characterized by hardened tissue in the penis).

  • Other medical problems, smoking, drug use, and hypertension can be ascertained with a thorough examination of health history.

  • Blood tests can indicate conditions that may interfere with normal erectile function. These tests measure hormone levels, cholesterol, blood sugar, liver and kidney function, and thyroid function.

  • Urine is analyzed for protein (albumin), sugar (glucose), and hormone (testosterone) levels that may indicate diabetes mellitus, kidney dysfunction, and testosterone deficiency.

  • Ultrasound is used to evaluate blood flow, venous leak, signs of atherosclerosis, and scarring or calcification of erectile tissue.

  • Specific nerve tests are used in patients with suspected nerve damage as a result of diabetes or nerve disease.

  • Psychological causes may be identified by ruling out a physiological cause. A band of stamps or perforated tape is placed around the penis before sleep. An erection during the night will break the perforations, demonstrating that there is no organic cause for the erectile dysfunction.

  • The drug alprostadil may be injected into the penis to test for vascular problems.


  • Avoid nicotine, alcohol, and other drugs.

  • Your doctor may change your prescriptions if a medication has caused impotence.

  • Psychological counseling may be recommended.

  • Testosterone injections or skin patches are given if blood testosterone levels are low.

  • Hyperthyroidism or hypothyroidism is treated if necessary.

  • Bromocriptine therapy is given to correct elevated prolactin levels.

  • Oral medications known as selective enzyme inhibitors are increasingly used to treat erectile dysfunction. Most men can use these drugs safely. But men with cardiovascular disease need to take special precautions, and some men should not use these medications—for example, men who take nitrates for angina. The medications include:

Viagra (sildenafil): Viagra is effective in up to 80 percent of men with erectile dysfunction. The drug is taken one to two hours prior to sexual activity and requires sexual stimulation to work.

Levitra or Staxyn (vardenafil): In clinical studies, vardenafil has been shown to work quickly, provide consistent results, and improve sexual function in most men the first time they take the drug.

Cialis (tadalafil): Cialis has been shown in clinical trials to stay in the body longer than the other selective enzyme inhibitors. It promotes an erection within 30 minutes and enhances the ability to achieve an erection for up to 36 hours.

Stendra (avanafil): Stendra is taken as needed 30 minutes before sexual activity.

  • Common side effects of selective enzyme inhibitors include headache, reddening of the face and neck (flushing), indigestion, and nasal congestion. Cialis may cause muscle aches and back pain, which usually resolve on their own within 48 hours.

  • A special vacuum device may be used to produce an erection. Air is pumped out of a plastic tube placed securely over the penis, and the resulting vacuum pulls blood into the corpora cavernosa within a few minutes. The device is removed and a rubber band is placed at the base of the penis to maintain the erection.

  • Self-administered injections of alprostadil, a vasodilator drug, dilate the blood vessels in the penis to produce an erection. Your doctor will instruct you on the correct injection technique.

  • Alprostadil is also available in a self-administered suppository called Muse, which is inserted in the end of the penis.

  • Surgical implants for the penis are available. In one procedure, an inflatable device with a small fluid reservoir is inserted. In another, flexible rods are implanted that can be either bent upward to produce an erection or tucked close to the body.

  • In rare circumstances, your doctor may advise vascular surgery to improve blood flow to the penis. Risks include nerve damage and the creation of scar tissue, both of which are causes of impotence.


  • Have no more than two alcoholic beverages a day.

  • Don’t smoke.

  • If your erectile dysfunction is deemed to have a psychological cause, talk to a therapist about improving communication with your sexual partner.

When To Call Your Doctor

Call a doctor if you experience a persistent inability to achieve or maintain an erection. Also contact your doctor if new medications you are taking have caused a change in erectile function, or if work-related stress or other psychological factors are affecting your sexual abilities.

Reviewed by Sovrin M. Shah, M.D., F.A.C.S., Assistant Professor of Urology, Icahn School of Medicine at Mount Sinai, Pelvic Medicine and Reconstructive Surgery, Sol and Margaret Berger Department of Urology, Mount Sinai Beth Israel, and Phillips Ambulatory Care Center, New York, NY. Review provided by VeriMed Healthcare Network.