Introduction
Testosterone (also known as androgen) is the main male sex hormone. It enables an adolescent male to develop masculine characteristics, such as enlargement of the penis and testes, a deepening voice, facial and body hair, and increased muscle mass. Its continued production in adulthood stimulates sex drive and sperm production in men, as well as helping them to maintain muscle and bone mass.
Low levels of testosterone may be responsible for a decline in sperm count and sex drive, along with subtle changes in physical appearance. Insufficient testosterone is a major cause of fertility problems.
Symptoms
Indications of lowering testosterone levels include diminished sex drive, erectile dysfunction, low sperm count and enlarged breasts. Men whose testosterone levels begin to drop as they get older (a transition known as andropause) may experience symptoms that mimic those of menopause, such as hot flashes and mood swings.
Signs of a more prolonged and dramatic decline in testosterone production include loss of body hair, reduced muscle and bone mass (resulting in increased fractures), and shrinkage of the testes. In adolescent males, low testosterone levels may inhibit the development of genitals, muscle mass and facial hair, as well as the deepening of their voice.
Causes/Risk Factors
The brain's hypothalamus regulates testosterone production through gonadotropin-releasing hormone (GnRH). This signals the pituitary gland to produce luteinizing hormone (LH), which, in turn, stimulates production of testosterone in the testes. Usually, the brain can gauge if the testes are producing too little (or too much) testosterone, and decrease (or increase) the production of LH accordingly.
Any abnormality in the testes, the pituitary glad or the hypothalamus can result in low testosterone levels. This includes damage to the testes due to injury, surgery, testicular inflammation, tumours or tumour treatment (e.g., radiation or chemotherapy), or a defect in the pituitary gland or hypothalamus as a result of tumours, medications (e.g., opiates, prednisone and anabolic steroids) or health conditions such as HIV/AIDS, sarcoidosis, tuberculosis, fungal infection and autoimmune diseases.
In other cases, low testosterone levels may be related to genetic disorders, such as Klinefelter's syndrome, hemochromatosis, Kallmann's syndrome, Prader-Willi syndrome and myotonic dystrophy.
Aging may also be a factor in low testosterone levels, since production of LH declines as men age. Older men also have more of a protein called sex hormone binding globulin (SHBG). This binds to testosterone, reducing the amount of the hormone in the muscles and other tissues.
What You Can Do
Exercise (such as weight training), eating a nutritious diet based on the recommendations of Canada's Food Guide, and maintaining a healthy weight all play an important role in hormonal health and preventing problems such as low testosterone levels.
If you suspect that you may be experiencing low testosterone levels, consult your doctor. Know both your own medical history and your family medical history beforehand and be prepared to discuss any relationship issues or major life changes. Also, bring an up-to-date list of all your medications with you to your appointment.
If you're diagnosed with low testosterone levels, remember that it's a medical condition you can't control and is nothing to be ashamed of. Still, it's normal to feel upset. Give yourself permission to feel the emotions you do and to ask for (and receive) your family's support.
Low testosterone levels are often associated with depression, anger and fatigue. Counselling can help.
If you're receiving testosterone supplementation, get screened regularly for prostate cancer. Let your doctor know if you experience any trouble breathing or frequent or unusually long-lasting erections.
If you're getting testosterone supplementation in the form of a patch or gel, make sure that women or children don't touch the area of your skin where it's applied.
What can I take?
Testosterone supplementation will help to boost your body's testosterones levels. It can be taken in the form of injections, gels and patches, or gum tablets. As with any medication, there are side effects. These may include enlarged breasts and an increased risk of prostate cancer, and fluid build-up in patients with heart, kidney or liver disease.
Talk with your doctor or endocrinologist about whether testosterone supplementation might help and what form would work best for you.
Further Resources
Contact Health Canada at www.hc-sc.gc.ca/iyh-vsv/men-hommes_e.html or 1-866-509-1769.
