While high levels of testosterone are associated with bed-hopping sex drive, low levels are linked to an increased risk of diabetes, osteoporosis, and, perhaps most alarming, depression.
A study of 4,000 older guys found lower testosterone levels in those who were depressed. Lower testosterone can, in turn, lead to a decline in the sex hormone estradiol, which has antidepressant properties, says lead study author Osvaldo P. Almeida, MD, of the University of Western Australia.
How to boost your levels? Your doctor might suggest replacement therapies or, simply, lifestyle changes. “Obese men have lower testosterone, as do men who smoke, are physically inactive, or consume more than 28 drinks per week,” says Dr. Almeida.