Low testosterone, a form of hypogonadism, occurs when the body fails to produce an adequate supply of this hormone. This condition is more prevalent as men age, occurring in about 20 percent of men over 60 years of age and increasing to as much as 50 percent in men over 80 years of age. While testosterone is thought of as the male hormone, it is necessary for female functioning as well, and women may also suffer from low testosterone.
Testosterone is a sex hormone naturally produced within the body. In men, this hormone helps to maintain sperm production, control sex drive, and regulate muscle mass and bone health. The pituitary gland and the brain control the production of testosterone which is secreted through the testicles.
Symptoms of Low Testosterone
Symptoms of low testosterone in men may include increased body fat, enlarged breasts, reduced muscle mass, diminished bone density and decreased energy. Sexual symptoms may include:
- Low libido (sex drive)
- Inability to reach orgasm
- Erectile dysfunction
- Low sperm count
- Diminished volume of seminal fluid
- Smaller or softer testicles
Men with low testosterone may also experience sadness, irritability, or depression.
Causes of Low Testosterone
The causes of low testosterone in men can vary and may include:
- Injury or infection of the testicles
- Treatment for testicular cancer
- Hormonal disorders
- Infections or chronic diseases
- Nutritional deficiencies
- Andropause (male menopause) due to natural aging
Some medications and certain genetic conditions can also lower a man's testosterone reading. Men who are hypertensive, obese, or who have elevated cholesterol levels may also suffer from low testosterone levels.
Diagnosis of Low Testosterone
To diagnose low testosterone, the doctor will perform a physical examination and review all of the patient's symptoms. Testosterone levels are measured with a blood test, but other diagnostic tests may be administered as well, including:
- Sperm count
- PSA test for prostate cancer
The hematocrit, which measures the red blood cell count, is taken because testosterone treatment can result in an increase of red blood cells.
Complications of Low Testosterone
In addition to negatively affecting quality of life and intimate relationships, low testosterone can be a factor in several disease conditions. Recent research suggests that men with low testosterone are at increased risk of developing diabetes, osteoporosis, and cardiovascular disease.
Treatment of Low Testosterone
Treatments for low testosterone involve replacing the hormone in the body. Often referred to as testosterone replacement therapy, these methods include administering the hormone through:
- Gel, cream, or patches applied to the skin
- Subcutaneous pellets
- Oral inserts (sublingual or buccal)
This treatment is effective in restoring normal testosterone levels in the male body and reducing symptoms. Testosterone replacement therapy is considered a lifelong treatment option. It is important that men taking testosterone be carefully monitored by their doctors.
Risks of Testosterone Treatment
Men treated with testosterone are at an increased risk of developing an enlarged prostate or urinary tract symptoms. Patients with kidney, liver, or heart problems may increase their risk of edema (fluid retention) by taking testosterone. Testosterone can also exacerbate sleep apnea. Though used as a fertility treatment in the short term, the long-term use of testosterone may interfere with fertility. Testosterone treatments are not usually recommended for men who have been treated for prostate or breast cancer.
Low Testosterone in Women
While testosterone is thought of as the male hormone, it is necessary for female functioning as well. Testosterone can be prescribed for women on an off-label basis as therapy for symptoms of menopause, such as hot flashes or vaginal dryness. Research has shown that women after menopause may also benefit from testosterone therapy which can:
- Increase mental clarity
- Help maintain mood balance
- Relieve fatigue
- Increase bone density
- Decrease body fat
- Restore libido
Testosterone does not increase the risk of cancer in women and has been shown to offer protection against Type 2 diabetes and cardiovascular disease. Testosterone therapy for women has not yet been approved by the FDA and so is not covered by insurance in the United States.
- National Institutes of Health
- Centers for Disease Control and Prevention
- Eunice Kennedy Shriver National Institute of Child Health and Human Development
- U.S. Department of Health & Human Services
- U.S. National Library of Medicine