Causes of Low Testosterone Levels in Males

Testosterone is a hormone produced naturally in humans, and its deficiency is characterized by a number of physiological and psychological side effects. While some congenital conditions cause low testosterone, it can also result from injury, disease, infection, and the aging process. Doctors can treat this condition by administering pharmaceutical testosterone.

What Is Testosterone?

• Testosterone is a naturally occurring steroid hormone produced in the testes of males (where it produces sperm), in small amounts in female ovaries, and in the adrenal glands of both sexes. It binds to the androgen receptors in muscle tissue to stimulate muscle growth by increasing protein synthesis inside of muscle cells. Testosterone also promotes bone density and the production of red blood cells. During puberty, testosterone causes masculine characteristics such as a deepening of the voice and increased facial and body hair.

Symptoms of Deficiency

• The absence or decline of natural testosterone production can produce a number of deleterious side effects, including decreased skeletal muscle mass, low bone density (osteoporosis), low red blood cell counts (mild anemia). Men might also experience a higher percentage of body fat or the redistribution of adipose tissue. Declining libido, erectile dysfunction, gynecomastia (development of male breasts), fatigue, depression, and poor memory and concentration may also occur.

  Men with testosterone deficiencies might also suffer from high blood pressure, heightened risk of heart attack, arteriosclerosis (build up of plaque in, and hardening of the arteries), and changes in blood serum cholesterol.

Congenital Causes

• Two genetic abnormalities can cause low testosterone in men. Klinefelter's syndrome occurs when the male possesses an extra X chromosome; men with this condition often lack male characteristics. Kallman syndrome results when the hypothalamus produces low levels of gonadotropin-releasing hormone, which is a precursor needed for testosterone production. Men born without testicles can also suffer low levels of testosterone.

Alcohol and Stress

• Alcohol can induce as much as a 20 percent decrease in serum testosterone (amount found in the blood). Over time, the liver damage accrued by alcoholics can reduce this to 50 percent. Periods of intense stress can also result in low testosterone.

Injury and Disease

• Men can also experience a decline in testosterone caused by cirrhosis of the liver, kidney failure, hypertension (high blood pressure), AIDS, sarcoidosis (a disease that causes inflammation of lung and organ tissue), and injuries to the testicles, hypothalamus, or pituitary gland.

  Syphilis, meningitis, and mumps are all infections that can cause low testosterone. Additionally, some medications, chemotherapy, and radiation treatments can also cause testosterone levels to drop.

  Obesity, and both Type I and Type II Diabetes can also cause low testosterone.

Aging

• A man's natural production of testosterone begins to decline after 25 at a rate of about two percent per year. By age 80, a man produces only about 20 percent of his peak testosterone levels.

Treatment

• Doctors can administer human chorionic gonadotropin (HCG) or gonadotropin releasing hormone to treat Kallman syndrome. All other causes of low testosterone are treated by endogenous (externally produced) synthetic testosterone. When treatment is used to reverse or alleviate low testosterone symptoms brought about by the aging process, this treatment is referred to as hormone replacement therapy.