andropause - male equivalent of the menopause. By the time men are between the ages of 40 and 55, they can experience a phenomenon similar to the female menopause, called andropause. Unlike women, men do not have a clear-cut signpost such as the cessation of menstruation to mark this transition. It is distinguished by a drop in testosterone levels.
Basically, testosterone levels drop and you're not 鹹濕 (lascivious) anymore, feel depressed .. feel high and depressed at intervals ... and other side effects.