Impotence, often called erectile dysfunction, is the inability to achieve or maintain an erection long enough to engage in sexual intercourse. Under normal circumstances, when a man is sexually stimulated, his brain sends a message down the spinal cord and into the nerves of the penis. The nerve endings in the penis release chemical messengers, called neurotransmitters, which signal the corpora cavernosa (the two spongy rods of tissue that span the length of the penis) to relax and fill with blood. As they expand, the corpora cavernosa close off other veins that would normally drain blood from the penis. As the penis becomes engorged with blood, it enlarges and stiffens, causing an erection. Problems with blood vessels, nerves, or tissues of the penis can interfere with an erection.
Causes of impotence may be psychological and physical. A man who has normal erectile responses during masturbation, or who regularly awakens with an erection, is likely to have a psychological basis for impotence.
The brain can help bring about an erection and it can prevent one. The upper portion of the brain known as the cerebral cortex can be involved in blocking the reflex action that causes an erection. By this means, thoughts or emotions can inhibit the erectile mechanism and cause so-called psychogenic impotence. Psychogenic impotence seems to feed on itself because its number one cause is fear of the possibility of failure to perform. Other factors in psychological impotence are guilt, depression, and boredom with the subject of sex stimulation.
Some of the physical factors that lead to impotence are:
- Clinical, locked-in depression.
- Deficiencies of testosterone or thyroid hormones.
- Elevated level of prolactin, another hormone involved in sexual function.
- Hardening of the arteries.
- Physical deformities of the penis.
- Spinal cord injuries.
- Weight problems
Symptoms of erectile dysfunction are the inability to have an erection or inability to sustain an erection long enough to finish having sex. An occasional difficulty may be considered normal, however, frequent episodes or prolonged problems lasting more than a couple of weeks may require further evaluation by a physician.
There is no specific treatment to prevent impotence. Perhaps the most important measure is to maintain general good health and avoid atherosclerosis--by exercising regularly, controlling weight, controlling hypertension and high cholesterol levels, and avoiding smoking. Avoiding excessive alcohol intake may also help.