As men age there is a gradual decline in testosterone levels. In the late forties and early fifties the levels are about a third to a half of what they were in the 20s. By the age of eighty to ninety testosterone has decreased by about 60%

There is a male version of menopause called andropause. When women go through menopause there is no confusing it because their periods stop. However with men the symptoms are not as obvious. These include reduced sex drive, erectile dysfunction, and decreased sexual satisfaction, fatigue, depression, irritability, aches and pains and stiffness.