When a man gets sexually aroused, blood flow to the genital area increases, readying the body for intercourse. The penis becomes enlarged and erect. In cases of Erectile Dysfunction (ED), however, this physical response doesn't happen as it should. And this isn't just a one-time or occasional occurrence; in fact, occasional failure to become aroused, or desiring sex less often than your partner, is perfectly normal. Stress, fatigue, and anxiety can all inhibit the body's response to sexual stimulation. The problem occurs when this lack of response happens persistently and on a regular basis say, more than 25% of the time. With ED, intercourse is difficult or impossible for encounter after encounter.

Statistics on ED indicate that it is not only a common problem, especially among older men, but also that it is undertreated. A few years ago, he Massachusetts Male Aging Study of middle-aged and older men showed that 34.8% of men aged 40 to 70 years had complete ED, which was strongly related to age, health status, and emotional function. According to the American Medical Association (AMA), an estimated 20 million American men, most older than 65, are affected; it is difficult to calculate an exact number because less than 10% actually seek treatment.

The following information is designed as a basic introduction to possible causes of and treatments for ED. If you suspect you have a problem, be sure to consult with your doctor or other healthcare professional.

Causes

Once thought to be a psychological condition, ED in most cases is now known to have a primary physical cause, such as a disease, an injury, or a side effect from a drug. For example, certain medications are known to interfere with the nerve signals that cause an erection. Heart disease, hardening of the arteries, and highblood pressure can cause damage to the blood vessels, interfering with blood flow to the penis. (In fact, since smoking is a major risk factor for these conditions, it is also a major risk factor for ED.) Diabetes can cause temporary or permanent damage to nerve tissues in the body, which may also interfere with erection. Men who are treated for prostate cancer sometimes develop ED as a result of their treatment. Other possible physical causes include alcoholism, liver failure, high cholesterol, hormonal abnormalities (such as low testosterone), and neurological disorders. In just about all cases of ED, even when there is a definite physical cause, there is a psychological component as well. Men typically feel anxiety, guilt, or depression which, in turn, makes the problem worse.

Treatments

The AMA estimates that 95% of ED cases are treatable through one of the following measures.

• Drug therapy: Sildenafil (Viagraź) was approved by the Food and Drug Administration in 1998 and is the only oral drug proven to treat ED. Taken an hour or so before sexual activity, it increases the concentration of a natural chemical in the penis that causes the blood vessels to dilate, which increases blood flow to the penis. Unlike injection therapy (see below), it doesn't cause an automatic erection; rather, it works in response to sexual stimulation. However, Viagraź isn't the right choice for all men. Men who have heart problems or who are taking medications that help widen the coronary arteries are not good candidates because the drug combination can make blood pressure dangerously low. Some men with hormonal imbalances may be helped by testosterone shots, pills, or skin patches. Additional medications, both oral and topical, are under investigation in clinical trials.

• Psychotherapy: Whether there is a physical cause or not, men may benefit from working with a therapist to learn techniques that can decrease anxiety associated with intercourse.

• Vacuum constriction device: This involves placing a plastic tube over the penis and pumping the air out of the tube, drawing blood into the penis and making it erect. An elastic band is placed around the base of the penis to maintain the erection.

• Penile injection therapy: Medication is injected directly into the side of the penis, causing the blood vessels to widen and erection to occur.

• Intraurethral therapy: A soft pellet of medication is inserted into the urethra, and then absorbed into the erection chambers of the penis.

• Surgery: Surgery may involve one of three procedures: implanting a device (prosthesis) that can cause the penis to become erect; reconstructing arteries to increase blood flow to the penis; or repairing the veins within the penis that are failing to keep sufficient blood within the organ.

All of these treatments have different complications and side effects, so it's important for men to work with their doctors to determine what's right for them.