Low testosterone can affect men by decreasing sexual function, causing physical changes, increasing sleep disturbances or causing emotional changes, according to Mayo Clinic. The effects vary from case to case and, in some men, are subtle or absent. Even without symptoms, a man with low testosterone should consider treatment.
Possible sexual function changes from decreased testosterone in men include reduced sexual desire and infertility, explains Mayo Clinic. Possible physical changes include an increase in body fat, a decrease in muscle mass and a decrease in the density of the bones. The mental changes decreased testosterone can cause in men include depression, memory loss, decreased concentration and a reduction in self-confidence. In some cases, it is difficult to know whether the decrease in testosterone causes these symptoms or they develop as a result of other conditions that often occur alongside decreased testosterone.
Testosterone decreases naturally with age, Mayo Clinic says. Abnormal decreases can occur because of problems in the testicles or the pituitary gland that controls the testicles, a condition known as hypogonadism. Treatments for low testosterone levels include testosterone therapy. This treatment carries its own risks of side effects, including acne, sleep apnea, decreased sperm production and shrunken testicles. Other side effects may include enlargement of breasts, enlargement of the prostate and an increased risk of deep vein thrombosis.