Erectile Dysfunction (ED)

Atherosclerosis may partially block blood flow to the legs (peripheral vascular disease). Usually, arteries to the penis are also blocked, decreasing the amount of blood flow to the penis and causing ED. Diabetes, high cholesterol levels, high blood pressure, and smoking contribute to atherosclerosis and therefore to ED.

Sometimes blood leaks out of the veins in the penis too fast, decreasing blood pressure in the penis and thus interfering with achieving or maintaining an erection (called veno-occlusive dysfunction).

If the nerves sending messages to the penis are damaged, ED can occur. In addition to causing atherosclerosis, diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more can also affect the nerves that supply the penis. Because nerves to the penis run along the prostate gland, prostate surgery (such as for cancer or an enlarged prostate) often causes ED.

Less common nerve disorders that cause ED include spinal cord injury, multiple sclerosis, and stroke. Also, prolonged pressure on the nerves in the buttocks and genital area (the so-called saddle area), as may occur during long-distance bicycle riding, can cause temporary ED.

Hormonal disturbances (such as abnormally low levels of testosterone) tend to decrease sex drive but can also result in ED.

In Peyronie disease Peyronie Disease Peyronie disease is a fibrous thickening that contracts and deforms the penis, distorting the shape of an erection. Many men have a small degree of curvature of their erect penis. Peyronie disease... read more , scar tissue develops inside the penis, resulting in curved and often painful erections and causing ED.

Drugs, including alcohol and illicit drugs such as cocaine and amphetamines, can also cause or contribute to ED.

Sometimes psychologic problems (such as performance anxiety or depression) or factors that decrease a man's energy level (such as illness, fatigue, or stress) cause or contribute to ED. Erectile dysfunction may be situational, involving a particular place, time, or partner.

Prolonged, painful erection (priapism Persistent Erection Persistent erection (priapism) is a painful, persistent, abnormal erection unaccompanied by sexual desire or excitation. It is most common in boys aged 5 to 10 years and in men aged 20 to 50... read more ) may damage the erectile tissue of the penis, leading to ED.

In men with ED, certain symptoms and characteristics are cause for concern. They include

Although ED may diminish a man's quality of life, it is not itself a dangerous condition. However, ED may be a symptom of a serious medical disorder. Because numbness in the groin or leg can be a sign of spinal cord damage, men who suddenly develop such numbness should see a doctor right away. Men who have other warning signs should call their doctor and ask how soon they need to be seen and examined.

Doctors first ask questions about the man's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause for ED and additional tests that may need to be done (see table Common Causes and Features of Erectile Dysfunction Common Causes and Features of Erectile Dysfunction ).

Doctors ask about

Even though men may be embarrassed to talk to their doctors about some of these subjects, the information is important in determining the cause of ED.

The physical examination focuses on the genitals and prostate, but doctors also look for signs of hormonal, nerve, and blood vessel disorders and examine the rectum.

The cause is sometimes clear from the history. For example, ED may occur soon after prostate surgery or beginning a new drug. One important clue is whether erections are present at night or on awakening. When erections are present, a physical cause is less likely than a psychologic cause because physical causes typically inhibit erections at all times. Other factors that suggest a psychologic cause are sudden development in a young healthy man, occurrence of symptoms only in certain situations, and resolution of ED without any treatment. Claudication or coolness or a blue color in the toes or feet may indicate a problem with the blood vessels such as peripheral vascular disease Overview of Peripheral Arterial Disease Peripheral arterial disease results in reduced blood flow in the arteries of the trunk, arms, and legs. Most often, doctors use the term peripheral arterial disease to describe poor circulation... read more or vascular disease caused by diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more .

Testing is usually needed. Laboratory tests include the measurement of the level of testosterone in the blood. If the testosterone level is low, doctors measure additional hormones. Depending on the results of the history and physical examination, blood tests may also be done to check for previously unrecognized diabetes, thyroid disorders, and lipid disorders. Usually, these tests provide doctors with enough information to plan treatment.

Occasionally, doctors inject a drug into the penis that stimulates erection and then use ultrasonography to assess blood flow in the arteries and veins of the penis. Rarely, doctors may recommend the use of a home monitor that detects and records erections during sleep.

Men who can develop but not sustain an erection may use a constriction ring. As soon as erection occurs, an elastic ring is placed around the base of the penis, helping prevent blood from flowing out and maintaining the firmness of the penis. If the man cannot develop an erection, a hand-held vacuum erection device can be applied over the penis. This device draws blood into the penis by exerting a gentle vacuum effect, after which the ring is placed on the base of the penis to retain the erection. Bruising of the penis, coldness of the tip of the penis, and lack of spontaneity are some drawbacks to this method. Sometimes a constriction ring and vacuum device are combined with drug therapy.

The primary drugs for ED are oral phosphodiesterase inhibitors. Other drugs include prostaglandins that are injected into the penis or inserted into the urethra. Oral phosphodiesterase inhibitors are used much more often than other drugs because they are simple to use and allow spontaneity in intercourse. Over-the-counter herbal remedies are sold for ED, but they are usually ineffective, contain hidden doses of a phosphodiesterase inhibitor, or both. The hidden phosphodiesterase inhibitor may expose the man to a drug with possible side effects.

Oral phosphodiesterase inhibitors (sildenafil, vardenafil, avanafil, and tadalafil) increase blood flow to the penis. These drugs work in the same way, but differ as to how long the effect lasts, their side effects, and their interactions with food. The effect of tadalafil lasts longer than those of the other drugs (up to 36 hours), which some men prefer.

Most phosphodiesterase inhibitors work best when taken on an empty stomach and at least 1 hour before sexual intercourse. Men who are taking nitrates (most often nitroglycerin for the treatment of angina but also recreational amyl nitrate ["poppers"]) should not take phosphodiesterase inhibitors because the combination can cause blood pressure to drop to unsafe levels. Other temporary side effects of phosphodiesterase inhibitors include flushing, vision abnormalities (including abnormal color perception), and headache. Priapism Persistent Erection Persistent erection (priapism) is a painful, persistent, abnormal erection unaccompanied by sexual desire or excitation. It is most common in boys aged 5 to 10 years and in men aged 20 to 50... read more (prolonged erection) develops very rarely and may require emergency medical treatment. In rare instances, men have reported blindness or hearing loss after taking phosphodiesterase inhibitors, but it is not clear whether the phosphodiesterase inhibitors have been the cause.

Alprostadil (the prostaglandin PGE1) alone or in combination with papaverine and phentolamine may be directly injected into the side of the penis using a very thin needle, causing a suitable erection in most men. An alprostadil suppository may be inserted into the urethra using a straw-like applicator. These therapies may cause priapism and penile pain. Usually, the doctor guides the man to administer the drug himself during an office visit. After this, men may give themselves these drugs at home. An alprostadil suppository may be combined with an oral phosphodiesterase inhibitor for men in whom oral drugs are not effective.

For some men, drug therapy is not effective or acceptable. In these men, surgery to implant a penile prosthesis may be done. Prostheses can take the form of rigid silicone rods or hydraulically operated devices that can be inflated and deflated. Both involve the risks of general anesthesia, infection, and prosthetic malfunction.