日中関係

Surgery (for example, prostate surgery) can injure nerves and arteries near
the penis, causing impotence. Injury to the penis, spinal cord, prostate,
bladder, and pelvis can lead to impotence by harming nerves, smooth
muscles, arteries, and fibrous tissues of the corpora cavernosa.

Also, many common medicines produce impotence as a side effect. These
include high blood pressure drugs, antihistamines, antidepressants,
tranquilizers, appetite suppressants, and cimetidine (an ulcer drug).

Experts believe that psychological factors cause 10 to 20 percent of cases
of impotence. These factors include stress, anxiety, guilt, depression, low
self-esteem, and fear of sexual failure. Such factors are broadly associated
with more than 80 percent of cases of impotence, usually as secondary
reactions to underlying physical causes.

Other possible causes of impotence are smoking, which affects blood flow in
veins and arteries, and hormonal abnormalities, such as insufficient
testosterone.