Testosterone is a male sex hormone that has an important role in sexual function , sperm production , build muscle , and tone of voice . Low levels of this hormone will cause a person to experience chronic fatigue , depression , erectile disorder , and less upright posture or reduced athletic ability .
Research shows that testosterone in normal amounts is essential to reduce the risk of diabetes and cardiovascular disease in men . Additionally , normal testosterone levels men live longer than men who lack this hormone .
Many myths circulated about one of the male hormones . Abraham Morgentaler , MD , a specialist urology at Harvard Medical School and author of Testosterone for Life will answer it for you .