Low Testosterone

The hormone testosterone promotes development of male sexual characteristics and impacts muscle bulk, bone growth, energy levels, sense of well being, adequate levels of red blood cells and sexual function. Testosterone deficiency (TD), also referred to as hypogonadism, affects 5-8 million men in the United States. Thirty percent of men ages 40-79 are affected.

Are there different types?

There are two types of testosterone deficiency. Primary testosterone deficiency is the failure of testicles to produce adequate amounts of the hormone. Secondary testosterone deficiency involves failure of the pituitary gland to send proper signals from the brain to the testicles.

What causes it?

Normal aging can cause primary testosterone deficiency as can autoimmune disorders (such as Addison's disease and hypoparathyroidism), genetic disorders (such as Turner and Klinefelter syndromes), infections, liver and kidney disease, hemochromatosis (the body absorbing too much iron), radiation exposure, injury to or surgery on sex organs, stress, alcoholism and cancer treatments.

Secondary testosterone deficiency may be caused by obesity, HIV/AIDS, inflammatory diseases (such as sarcoidosis, tuberculosis), pain and hormone medications, pituitary disorders, Kallmann syndrome, rapid weight loss, nutritional deficiencies, bleeding and brain surgery.

What are the effects?

  • Decrease in muscle mass
  • Decreased growth of sexual organs
  • Changes in cholesterol levels
  • Mild anemia
  • Fragile bones
  • Decreased body hair
  • Changes in fat distribution
  • Sleep disturbances
  • Sexual dysfunction
  • Lack of motivation or self-confidence
  • Depression
  • Trouble remembering or concentrating
  • Fatigue

Researchers see definite connections between the most common men's health threats (heart disease, stroke, depression and prostate cancer) and testosterone deficiency, but are unsure if the condition/disease lowers levels of testosterone or if lower testosterone contributes to the development of the condition. Research on this issue is ongoing.

How do I find out if I have it?

A visit to the doctor and blood tests can determine if you have a testosterone deficiency. It may be necessary to have more than one blood test because testosterone levels fluctuate during the day. Doctors usually prefer testing in the morning when levels are highest. Testosterone levels less than 300 nanograms per deciliter (ng/dL) can indicate low testosterone.

What can I do?

Some researchers have found that a change in lifestyle, including diet and exercise, offer a solution to low testosterone. However, if medical treatment is required, there are several options.

  • Intramuscular injections
  • Testosterone patch
  • Testosterone gel
  • Mucoadhesive material applied above the teeth twice a day
  • Oral tablets
  • Long-acting subcutaneous implant
  • Testosterone stick (applied like deodorant)

Each of the treatments above offers different levels of testosterone replacement, and has advantages and disadvantages. The treatment best suited for you will be determined by you and your doctor.