Answer
Serum testosterone levels decline with advancing age: in a male of about 20 years of age the serum testosterone secretion is about five times greater than that in a man 80 years of age (1.5 mg/day)
Work Step by Step
Sperm counts are lower in older men, and libido declines with advancing age. The decrease in the production of testerone --and its derivatives-- is also responsible for loss of sexual sensitivity and the increase in frequency of erectile dysfunction (ED) among older males. The level of ED among men in their sixties is only about 20%. However, by the time men are in their eighties, the average level of ED has advanced to about 50% . Nevertheless, the large majority of men with ED can still ejaculate.
