The list of symptoms associated with low testosterone (low T) is extensive and they can negatively affect a man’s quality of life. Testosterone levels for men begin to dip after age 30 at a pace of about 1% each year. This is a normal part of aging. Low testosterone levels can result in a reduced sex drive, loss of physical performance, increased body fat, fatigue, decreased strength, swollen breast tissue, and hot flashes, among other symptoms.