Impotence (Erectile Dysfunction)


What Is It?

Erectile dysfunction, also called impotence, means that a man’s penis doesn’t get hard enough to have intercourse. The man cannot get or maintain an erection. This condition affects approximately 30 million men in the United States. (Erectile dysfunction is not the same as premature ejaculation, retarded ejaculation or infertility.)

The major causes of erectile dysfunction include:

  • Vascular (blood vessel) disease — Because erections are caused by the buildup of blood in the shaft of the penis, poor blood flow in the penis can result in problems with erections. Damage to blood vessels can be caused by hardening of the arteries (atherosclerosis) or damage to blood vessels from trauma. Vascular disease is believed to be the most common medical cause of erectile dysfunction.

  • Nerve damage (neuropathy) — Nerves must be working normally for a man to be able to get and keep an erection. Nerve damage can result from diabetes, multiple sclerosis, prostate surgery or damage to the spinal cord.

  • Psychological factors — Sexual problems sometimes are caused by psychological issues such as depression, anxiety, guilt or fear. At one time, psychological factors were thought to be the major cause of erectile dysfunction. Doctors now know that physical factors are present in most men with erectile dysfunction. However, embarrassment or “performance anxiety” can make a physical problem worse. Erectile dysfunction caused only by psychological causes is found most commonly in young men.

  • Medications — Many medications cause problems with sexual function, including drugs prescribed for high blood pressure, depression, heart disease and prostate cancer.

  • Hormonal problems — Abnormal levels of certain hormones, such as testosterone, thyroid hormone and a pituitary hormone known as prolactin, can interfere with erections and sex drive (libido). This is an uncommon cause of erectile dysfunction.


A man with erectile dysfunction has either a problem getting an erection or difficulty maintaining one. This usually interferes with sexual activity by preventing penetration during intercourse.

Erectile dysfunction can occur suddenly or gradually. Some men slowly lose the firmness of their erections or how long the erections last. In other men, especially those whose impotence is largely caused by psychological factors, the problem may occur unpredictably and can improve at any time. Despite their difficulties with erections, men with impotence often continue to have normal orgasm and ejaculation.


Your doctor first will ask you about your medical history. This is to learn if any medical conditions might be causing the erectile dysfunction, including vascular, neurological and hormonal disorders. Since vascular disorders affect the entire body, many men who have erectile dysfunction because of vascular disease also have a history of heart disease, stroke or poor circulation in their legs. Neurological problems can contribute to erectile dysfunction in men with a history of diabetes and spinal-cord injury. They also can cause symptoms in other parts of the body, such as numbness or weakness in legs. In men with abnormal hormone levels, reduced sex drive often accompanies erectile dysfunction. Your doctor also will review the medications you are taking, including over-the-counter medications and herbal remedies.

Your doctor also will ask about your sex life. This sometimes is called a psychosexual history. It includes questions about the quality of your sexual relationships.

Your doctor will examine you, including your penis and testes, to look for evidence of underlying medical problems. Your blood may be tested for blood sugar (to check for diabetes), cholesterol and levels of certain hormones.

Occasionally, a doctor may order additional tests, such as a nocturnal penile tumescence study. This is a way to assess how often you get erections while you sleep. A Doppler ultrasound of the blood vessels in the penis is another test that occasionally will show a cause for poor erections.

Although your doctor may not be able to give you a specific reason why you have developed erectile dysfunction, many of the treatments work well no matter what caused the problem, so extensive testing may not be necessary.

Expected Duration

How long your erectile dysfunction lasts depends upon what causes it and how quickly your treatment starts to work. The important thing to remember is that erectile dysfunction is treatable in all age groups.


Little is known about how to prevent erectile dysfunction. However, avoiding cigarette smoking and maintaining normal blood pressure and cholesterol levels can help because smoking and High cholesterol can affect blood vessels. Also, men with diabetes should strive to keep blood sugar levels under control. Because certain medications have been associated with erectile dysfunction, ask your doctor about possible side effects before you start using any new prescription.


There are many effective treatments for erectile dysfunction. The most popular option is a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors, which includes sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis). These drugs are taken in pill form, zero to 60 minutes before sexual activity. They work in approximately 70 percent of men, but are less effective in men with neurological causes of erectile dysfunction such as nerve damage from prostate surgery, diabetes or spinal-cord injury. PDE5 drugs can cause minor side effects such as flushing and headache, but they have been shown to be safe in most men, including those with heart disease. However, PDE5 drugs can interact with other medications and cause dangerously low blood pressure. In particular, they should never be taken with nitroglycerin or other nitrate medications that commonly are used to treat heart disease. Men with prostate enlargement who take alpha-blocker drugs such tamsulosin (Flomax) or doxazosin (Cardura) also should probably avoid PDE5 drugs.

If sildenafil or related drugs don’t work or cannot be used because of potential side effects, your doctor can recommend other therapies. The drug alprostadil (Caverject, Edex, Muse) causes blood vessels to widen. This can allow blood to flow more freely in the penis, leading to an erection. The drug can be injected with a tiny needle, or a small pellet can be inserted into the opening of the urethra (urine tube). Suppositories like this are effective in approximately two-thirds of men. Injections are effective about 80 percent of the time.

Men whose blood test results are abnormal can try taking hormones.

Psychological therapy such as counseling, behavioral therapy or couples’ therapy can be effective in men whose impotence is caused primarily by psychological factors.

Men who do not benefit from medical or psychological treatment often will have success with mechanical or prosthetic devices. External devices, known as vacuum erection devices, are safe and highly effective, but many men and their partners find them unappealing. Another option is a surgically placed penile implant. However, because implants require surgery (with the risk of surgical complications), only 10 percent of men with erectile dysfunction choose this option. Vascular (blood vessel) surgery sometimes is recommended for young, healthy men who develop impotence after trauma to the groin. Unfortunately, the long-term success rates of this surgery are not known.

When To Call A Professional

A man should speak to his doctor if he has trouble getting or keeping an erection over a period of three months or more. Because of embarrassment or shame, many men with erectile dysfunction don’t talk to their doctors. They hope that the problem will go away on its own. However, this often is not the case. Although erectile dysfunction caused by psychological factors may get better on its own, treatment is needed is the problem is caused by a physical factor.


In general, the prognosis for men with erectile dysfunction is excellent. Although most cases of impotence have medical causes that cannot be cured, there are many treatment options that will restore sexual function. In addition, there are several permanently curable forms of the disorder, including erectile dysfunction caused by psychological problems, hormonal disorders and traumatic injury to the penile arteries.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.