It seems reasonable to believe that many if not all men pass through a climacteric period somewhat similar to that of women, usually in a less severe but perhaps more prolonged form. The cessation of menstruation in the female at the so-called change of life has been tangible evidence for ages that the woman is having a decline in her sex function and is approaching the end of her child-bearing period. This cessation of menstruation in the female, usually called the menopause, is not the climacteric but represents only visible evidence that the woman is having endocrine imbalance. The endocrine dysfunction, plus the imbalance of equilibrium between the two divisions of the autonomic nervous system, with evidence at times of disturbance in the psychic centers, is the climacteric. The true climacteric is due primarily to decline of function of the sex glands. Decline of sex function is not limited to