Impotence or Erectile Dysfunction (ED) is defined as the consistent inability to achieve and maintain an erection sufficiently to permit satisfactory sexual intercourse. Many men experience erectile failure one or more times during their adult lives (usually due to anger, Stress or drinking) but this clears up quickly and no treatment is needed.

By definition, Erectile Dysfunction, can be a total inability to achieve erection, an inconsistent ability to do so, or a tendency to sustain only brief erections. These variations make defining impotence and estimating its incidence difficult. Estimates range from 15-30 million, depending on the definition used. According to the National Ambulatory Medical Care Survey (NAMCS), for every 1,000 men in the United States, 7.7 physician office visits were made for impotence in 1985. By 1999, that rate had nearly tripled to 22.3 visits. The increase happened gradually, presumably as treatments such as vacuum devices and injectable drugs became more widely available and discussing erectile function became accepted. Perhaps the most publicized advance was the introduction of the oral drug sildenafil citrate (Viagra) in March 1998. NAMCS data on new drugs show an estimated 2.6 million mentions of Viagra at physician office visits in 1999, and one-third of those mentions occurred during visits for a diagnosis other than impotence.

In older men, impotence usually has a physical cause, such as disease, injury, or side effects of drugs. Any disorder that causes injury to the nerves or impairs blood flow in the penis has the potential to cause impotence. Incidence increases with age: About 5% of 40-year-old men and between 15-25% of 65-year-old men experience impotence. But it is not an inevitable part of aging.

Impotence is treatable at any age, and awareness of this fact has been growing. More men have been seeking help and returning to normal sexual activity because of improved, successful treatments for impotence.

Frequently Asked Questions

What is the difference between impotence and erectile dysfunction?
Nothing except the more modern politically correct term is erectile dysfunction, especially in the US. The rest of the world, especially Europe and Asia still use the term impotence to describe this condition.

How does an erection occur?
The penis contains two chambers called the corpora cavernosa, which run the length of the organ (Figure 1). A spongy tissue fills the chambers. The corpora cavernosa are surrounded by a membrane, called the tunica albuginea. The spongy tissue contains smooth muscles, fibrous tissues, spaces, veins, and arteries. The urethra, which is the channel for urine and sperm, runs along the underside of the corpora cavernosa.

Erection begins with sensory or mental stimulation, or both. Impulses from the brain and local nerves cause the muscles of the corpora cavernosa to relax, allowing blood to flow in and fill the spaces. The blood creates pressure in the corpora cavernosa, making the penis expand. The tunica albuginea helps trap the blood in the corpora cavernosa, thereby sustaining erection. When muscles in the penis contract to stop the inflow of blood and open outflow channels, erection is reversed.

Arteries (top) and veins (bottom) penetrate the long, filled cavities running the length of the penis - the corpora cavernosa and the corpous sponglosum. Erection occurs when relaxed muscles allow the corpora cavernosa to fill with excess blood fed by the arteries, while drainage of blood through the veins is blocked.

How is impotence diagnosed?
Medical and sexual histories help define the degree and nature of impotence. A medical history can disclose diseases that lead to impotence, while a simple recounting of sexual activity might distinguish between problems with sexual desire, erection, ejaculation, or orgasm.

A physical examination can give clues to systemic problems. For example, if the penis is not sensitive to touching, a problem in the nervous system may be the cause. Abnormal secondary sex characteristics, such as hair pattern, can point to hormonal problems, which would mean that the endocrine system is involved. The examiner might discover a circulatory problem by observing decreased pulses in the wrist or ankles. And unusual characteristics of the penis itself could suggest the source of the problem--for example, a penis that bends or curves when erect could be the result of Peyronie's disease.

Several laboratory tests can help diagnose impotence. Tests for systemic diseases include blood counts, urinalysis, lipid profile, and measurements of creatinine and liver enzymes. Measuring the amount of testosterone in the blood can yield information about problems with the endocrine system and is indicated especially in patients with decreased sexual desire.

Monitoring erections that occur during sleep (nocturnal penile tumescence) can help rule out certain psychological causes of impotence. Healthy men have involuntary erections during sleep. If nocturnal erections do not occur, then impotence is likely to have a physical rather than psychological cause. Tests of nocturnal erections are not completely reliable, however. Scientists have not standardized such tests and have not determined when they should be applied for best results.

A psychosocial examination, using an interview and a questionnaire, reveals psychological factors. A man's sexual partner may also be interviewed to determine expectations and perceptions during sexual intercourse.

What causes impotence?
Since an erection requires a precise sequence of events, impotence can occur when any of the events is disrupted. The sequence includes nerve impulses in the brain, spinal column, and area around the penis, and response in muscles, fibrous tissues, veins, and arteries in and near the corpora cavernosa.

Medically, things like hypertension or high blood pressure, coronary artery or heart disease, "hardening of the arteries" (arteriosclerosis), hyperlipidemia, elevated cholesterol levels, diabetes, stroke, neurologic problems like multiple sclerosis, Parkinson's disease and spinal cord injury, are the most common causes. Surgery or radiation to correct cancer on the pelvic area (colon, bladder, prostate) can cause impotence.

In addition, many common medicines e.g. blood pressure drugs, antihistamines, antidepressants, tranquilizers, appetite suppressants, and cimetidine (an ulcer drug), can produce impotence as a side effect.

Experts believe that psychological factors such as stress, anxiety, guilt, depression, low self-esteem, and fear of sexual failure cause 10 to 20% of impotence cases. Men with a physical cause for impotence frequently experience the same sort of psychological reactions (stress, anxiety, guilt, depression).

Other possible causes are smoking, which affects blood flow in veins and arteries, and hormonal abnormalities, such as not enough testosterone.

Is impotence a disease?
No, it is usually more of a symptom or side effect of something else. That "something else" can be quite serious, even life threatening in some cases, so the cause of impotence needs to be determined and corrected if possible. This obviously means you should let your family doctor know if you are one experiencing erectile problems. So even if you have tried some initial treatments without success, talk to your doctor about other treatment possibilities. This is often a good time for referral to an ED specialist, usually a urologist.

Is impotence treatable? How is impotence treated?
Yes, often the underlying cause can be determined with a few simple tests and in some cases corrected. Even if the cause is not correctable (i.e. high blood pressure, prostate cancer, atherosclerosis, diabetes, etc) nearly every man can have his erectile dysfunction treated and satisfactory erections restored.

Most physicians suggest that treatments proceed from least to most invasive. Cutting back on any drugs with harmful side effects is considered first. For example, drugs for high blood pressure work in different ways. If you think a particular drug is causing problems with erection, tell your doctor and ask whether you can try a different class of blood pressure medicine.

Psychotherapy and behavior modifications in selected patients are considered next if indicated, followed by oral or locally injected drugs, vacuum devices, and surgically implanted devices. In rare cases, surgery involving veins or arteries may be considered.

Experts often treat psychologically based ED using techniques that decrease the anxiety associated with intercourse. The patient's partner can help with the techniques, which include gradual development of intimacy and stimulation. Such techniques also can help relieve anxiety when ED from physical causes is being treated.

Drugs for treating ED can be taken orally, injected directly into the penis, or inserted into the urethra at the tip of the penis. In March 1998, the Food and Drug Administration approved Viagra, the first pill to treat ED. Taken an hour before sexual activity, Viagra works by enhancing the effects of nitric oxide, a chemical that relaxes smooth muscles in the penis during sexual stimulation and allows increased blood flow.

While Viagra improves the response to sexual stimulation, it does not trigger an automatic erection as injections do. The recommended dose is 50 mg, and the physician may adjust this dose to 100 mg or 25 mg, depending on the patient. The drug should not be used more than once a day. Men who take nitrate-based drugs such as nitroglycerin for heart problems should not use Viagra because the combination can cause a sudden drop in blood pressure.

Additional oral medicines may soon be available to treat ED. Vardenafil and Cialis are being tested for safety and effectiveness. Both of these drugs work like Viagra by increasing blood flow to the penis. A third drug being tested, Uprima, works on the brain and nervous system to trigger an erection.

Oral testosterone can reduce ED in some men with low levels of natural testosterone, but it is often ineffective and may cause liver damage. Patients also have claimed that other oral drugs--including yohimbine hydrochloride, dopamine and serotonin agonists, and trazodone--are effective, but the results of scientific studies to substantiate these claims have been inconsistent. Improvements observed following use of these drugs may be examples of the placebo effect, that is, a change that results simply from the patient's believing that an improvement will occur.

Many men achieve stronger erections by injecting drugs into the penis, causing it to become engorged with blood. Drugs such as papaverine hydrochloride, phentolamine, and alprostadil (marketed as Caverject) widen blood vessels. These drugs may create unwanted side effects, however, including persistent erection (known as priapism) and scarring. Nitroglycerin, a muscle relaxant, can sometimes enhance erection when rubbed on the penis.

A system for inserting a pellet of alprostadil into the urethra is marketed as Muse. The system uses a prefilled applicator to deliver the pellet about an inch deep into the urethra. An erection will begin within 8 to 10 minutes and may last 30-60 minutes. The most common side effects are aching in the penis, testicles, and area between the penis and rectum; warmth or burning sensation in the urethra; redness from increased blood flow to the penis; and minor urethral bleeding or spotting.

Research on drugs for treating ED is expanding rapidly. Patients should ask their doctor about the latest advances.

Mechanical vacuum devices cause erection by creating a partial vacuum, which draws blood into the penis, engorging and expanding it. The devices have three components: a plastic cylinder, into which the penis is placed; a pump, which draws air out of the cylinder; and an elastic band, which is placed around the base of the penis to maintain the erection after the cylinder is removed and during intercourse by preventing blood from flowing back into the body (Figure 2).

Figure 2: A vacuum-constrictor device causes an erection by creating a partial vacuum around the penis, which draws blood into the corpora cavernosa. Pictured here are the necessary components: (a) a plastic cylinder, which covers the penis; (b) a pump, which draws air out of the cylinder; and (c) an elastic ring, which, when fitted over the base of the penis, traps the blood and sustains the erection after the cylinder is removed.

One variation of the vacuum device involves a semirigid rubber sheath that is placed on the penis and remains there after erection is attained and during intercourse.

Surgery is another alternative and usually has one of three goals:

• To implant a device that can cause the penis to become erect.
  Implanted devices, known as prostheses, can restore erection in many men with ED. Possible problems with implants include mechanical breakdown and infection, although mechanical problems have diminished in recent years because of technological advances.
• To reconstruct arteries to increase flow of blood to the penis.
  Malleable implants usually consist of paired rods, which are inserted surgically into the corpora cavernosa. The user manually adjusts the position of the penis and, therefore, the rods. Adjustment does not affect the width or length of the penis.
• To block off veins that allow blood to leak from the penile tissues.
  Inflatable implants consist of paired cylinders, which are surgically inserted inside the penis and can be expanded using pressurized fluid (see figure 3). Tubes connect the cylinders to a fluid reservoir and a pump, which are also surgically implanted. The patient inflates the cylinders by pressing on the small pump, located under the skin in the scrotum. Inflatable implants can expand the length and width of the penis somewhat. They also leave the penis in a more natural state when not inflated.

Figure3: With an inflatable implant, erection is produced by squeezing a small pump (a) implanted in a scrotum. The pump causes fluid to flow from a reservoir (b) residing in the lower pelvis to two cylinders (c) residing in the penis. The cylinders expand to create the erection.

Surgery to repair arteries can reduce ED caused by obstructions that block the flow of blood. The best candidates for such surgery are young men with discrete blockage of an artery because of an injury to the crotch or fracture of the pelvis. The procedure is less successful in older men with widespread blockage.

Surgery to veins that allow blood to leave the penis usually involves an opposite procedure called "intentional blockage". Blocking off veins (ligation) can reduce the leakage of blood that diminishes the rigidity of the penis during erection. However, experts have raised questions about the long-term effectiveness of this procedure, and it is rarely done.

How common is impotence/erectile dysfunction?
Unfortunately, very common. A recent study done in Massachusetts showed that 52% of men between ages 40-70 had some degree of erectile difficulty. It is estimated that between 20-30 million men in the US have erectile dysfunction, only a small percentage of them have yet to seek or receive treatment.

What about my partner?
Impotence or erectile dysfunction is not just a man's problem. It's a "couple's disorder" involving your partner and discussing how this is affecting both of you is very important and often leads to better communication and understanding between couples and certainly to easier solutions.

Isn't most impotence/erectile dysfunction an emotional or psychological problem?
Not really. While it is true that problems with erections can cause great psychological stress for the man and the partner of the man who has it, the underlying cause of the problem in up to 90% of cases is a physical or medical one, like diabetes, heart disease or high blood pressure.

I am only 22 years old and am sexually inexperienced. Recently I am having difficulty keeping my erection during intercourse with my girlfriend. Do I have ED?
You are certainly are having erectile difficulties but unless you have one or more of the previously mentioned underlying medical conditions, your erectile difficulties are probably psychological and only temporary. Many men experience erectile failure on a temporary basis from time to time (often due to stress, monetary concerns, excessive alcohol intake, etc.) but these failures usually resolve themselves with a little time and patience. Having an understanding, non-demanding partner with whom you can talk frankly is a big help. If you continue to experience failure on a consistent basis, you should see your physician for a complete medical exam.

What treatments are available for diabetics?
I am a 51 yr old diabetic and take insulin, can my ED be treated? Yes, nearly all diabetics can be successfuly treated for ED. Treatment is easier and more successful if you watch you diet, exercise and keep your blood sugar under control. Many (57%) diabetics can be successfuly treated with oral medications. Others can be treated with vacuum therapy and some with penile injections. Penile implant surgery is also a choice for the diabetic and his partner.

What treatments are available for diabetics?
I am a 51 yr old diabetic and take insulin, can my ED be treated? Yes, nearly all diabetics can be successfuly treated for ED. Treatment is easier and more successful if you watch you diet, exercise and keep your blood sugar under control. Many (57%) diabetics can be successfuly treated with oral medications. Others can be treated with vacuum therapy and some with penile injections. Penile implant surgery is also a choice for the diabetic and his partner.