II.

Causes of Impotence

There are various causes of impotence. In primary anatomic impotence the genitals themselves may be faulty. In secondary impotence, functional causes such as psychological problems and side effects of drugs taken for other disorders account for the greatest number of cases.

The most common psychological factors contributing to impotence are stress in a man's life or difficulties in his sexual relationships. For example, if a man has suddenly lost his job, his feeling of failure may lead to temporary impotence. It is possible to tell if the cause of a man's impotence is solely psychological; if he still experiences normal erections during rapid eye movement (REM) sleep, there is unlikely to be any physical reason for his impotence when conscious. However, in some cases a physical condition that is not severe enough to produce impotence on its own may make a man more likely to develop impotence if minor psychological factors are also present.

Many drugs can contribute to impotence. Diuretics, tricyclic antidepressants, H2 blockers, beta-blockers, and hormones are among the most common; once the drug treatment is halted, normal erections typically resume (unless psychological problems have developed in the meantime).

Other causes of impotence have to do with physical conditions, disease, or trauma. Among these, diabetes mellitus accounts for 40 percent of the cases in the United States; vascular diseases, 30 percent; surgery on the pelvis or penis, 13 percent; spinal cord injury, 8 percent; endocrine (glandular) problems, 6 percent, and multiple sclerosis, 3 percent.