Testosterone Deficiency Symptoms

Testosterone is a key hormone in males that impacts not only sexual development and performance but hair growth, muscle development and even cardiovascular health. Low testosterone levels are associated with a number of health problems, but since levels vary widely in different individuals, making a determination of what is normal is difficult.

Definition

• Testosterone is a hormone in the form of a natural anabolic steroid secreted by the testes and, to a smaller degree, the adrenal gland. It is the most important of the male sex hormones.

  Men normally produce 40 to 60 times more testosterone than women.

Levels

• There are no established normal levels of testosterone in men because levels vary widely by age and individuals. Doctors in the United States generally consider anything below 300 nanograms per deciliter to be low, but those levels could be normal in an older man or too low in a man in his 30s.

  Testosterone levels peak in the late 20s, dropping an average of 1.5 percent a year after age 30. A man in his 80s usually has 20 to 50 percent as much of the hormone as a man in his late 20s.

Causes

• Low testosterone levels can be caused by congenital problems with the formation of the testes and the creation of the hormone.

  More commonly, lower levels are caused by aging, chronic illness, drugs, starvation, stress, head trauma, infections, cancers, surgeries, alcoholism, trauma to the testicles or the use of certain drugs.

Symptoms

• Symptoms of low testosterone in men are rare or often so subtle they are easy to miss.

  Common symptoms include loss of sex drive, erectile dysfunction and bone loss or bone fractures.

  Doctors also say any two of the following symptoms may indicate low testosterone: sleep disturbance, depression, lethargy and diminished physical performance.

Effects

• Testosterone is still being heavily researched. A University of Washington study published in 2006 in the Archives of Internal Medicine found that lower levels of the hormone were associated with higher death rates in men over 40.

  Low testosterone also reduces muscle mass and can cause weakness. It can also cause lower bone mass. A study by Dr. Michiaki Fukui published in Diabetes Care found a direct correlation between lower testosterone levels and a higher risk of heart disease. Lower levels also are associated with increased body fat as well as a higher risk of diabetes.

Therapies

• Doctors are not in agreement on when testosterone replacement is necessary. The American Association of Clinical Endocrinologists has revised its guidance to recommend hormone replacement therapy even in older men with what were once considered normal levels for that age.

  Replacement treatments include injections, patches, gels, subcutaneous pellets, as well as pills or capsules taken orally.