(See also Overview of Sexual Dysfunction in Men.)
Sex drive (libido) varies greatly among men and may be decreased temporarily by conditions such as fatigue or anxiety. Libido also tends to gradually decrease as a man ages. Persistently low libido may cause distress to a couple.
Occasionally, low libido can be a life-long problem that results from traumatic childhood sexual experiences or from learned suppression of sexual thoughts. Most often, however, low libido develops after years of normal sexual desire. Psychologic factors, such as depression, anxiety, and relationship problems, are often the cause. Chronic kidney disease can decrease libido. Some drugs (such as those used to treat depression, anxiety, or advanced prostate cancer) can decrease blood levels of testosterone and also lower libido.
When libido is decreased, men have fewer sexual thoughts and fantasies and less interest in sex, and they engage in sexual activity less frequently. Even sexual stimulation, by sights, words, or touch, may fail to provoke interest. Men with low libido often retain the capacity for sexual function and may sometimes continue to engage in sexual activity to satisfy their partner.
A blood test can measure the level of testosterone in the blood. The diagnosis of low testosterone (called hypogonadism) is based both on the man's description of his symptoms and his low blood levels of testosterone.
If the cause is psychologic, various psychologic therapies, including behavioral therapies, can help. Counseling can help the couple address relationship issues. Men should also understand the role of stress and its impact on physical function.
If the testosterone level is low, supplemental testosterone can be given, in the form of a patch or gel applied to the skin or as an injection. Such treatments were previously thought to slightly increase the risk of heart attack or stroke. However, the majority of studies have not confirmed these findings. Supplemental testosterone is not recommended unless a man's blood level of testosterone is low. If a drug appears to be the cause of low testosterone levels, a doctor may consider treating the man with a different drug.