The male climacteric is a more or less infrequent accompaniment to the process of ageing in males. Organic (or gonadal) degeneration, with testicular atrophy and hormone decline is possible; this may account for more obvious physiological factors, such as prostate enlargement and impotence. Psychoneurotic factors include breakdown revolving around general anxiety or psychogenic impotence, and over-reaction to life and mid-life changes and events, including destabilizing changes in family make-up or relationships, vocational changes including job loss, and deaths of friends or close relatives. The major symptoms include loss or marked decrease of energy, libido and purpose. These may be incident to depression and, in aggravated cases, can lead to suicide, psychosis or violence. The sufferer may destroy what remained initially unaffected; it is frequently his marriage, either legally by divorce or separation, or qualitatively. Thus the combination of female menopause and male mid-life in the same marriage is a time requiring special, mutual sensitivity and understanding, and possibly professional counselling.
It remains unclear whether these bodily changes should be viewed as entirely normal or evidence of ill health. Hormone therapy for ageing men, borrowing from what is known about female menopause, is in its infancy.
A number of 1992 and later studies suggest the gradual decline of testosterone levels in aging men, by as much as 30 to 50% between the ages of 48 and 80. Decreasing levels of testosterone may prompt symptoms such as decline in muscle mass, loss of bone density, buildup of body fat and decrease in energy. One German study found unusually high testosterone levels in a group of healthy men over 55, and lower levels among those in their 60's and 70's who suffered serious health problems.