Testosterone is a hormone, primarily produced in the testes in males and in the ovaries and adrenal glands in females. It is an androgen, meaning that it is responsible for the development and maintenance of sexual characteristics.
It is also involved in several key functions in the body such as maintaining bone density, maintaining muscle mass, regulating mood, cognitive function and energy levels.
In males, testosterone is important for the development of the penis, the testes and the scrotum.
It is also important for the pubertal development including facial and body hair, deeper voice and increased muscle mass. As regards to sexual functions, testosterone is very much a key player in the production of sperm, and helps maintaining the sexual drive (libido) in adult males.
A normal testosterone suggests that many of your bodily functions such as bone growth, muscle growth, energy levels and mood are in balance.
Being an important hormone for sexual characteristics and sexual function, measuring testosterone levels in men is most commonly indicated when investigating erectile dysfunction or infertility. When the body does not produce enough testosterone, also known as hypogonadism, symptoms may include lower sex drive, muscle weakness, decreased bone density and fatigue.
If you experience these symptoms, there might also be a reason to have your testosterone levels measured. Being important in bone health and mood, testing may also be indicated when investigating osteoporosis and mood disorders. Finally, testosterone can stimulate the growth of prostate cancer cells.
Therefore, measuring testosterone can help monitor the effectiveness of prostate cancer treatments aiming at reducing testosterone levels.
Low levels of testosterone may indicate a condition called hypogonadism or testosterone deficiency. The most common cause for hypogonadism is age related, since the production of testosterone slowly declines with increasing age.
Other underlying causes for low testosterone levels are obesity, high intake of alcohol, conditions in the testes or the pituitary gland, or certain painkillers. If a man recently has been treated with testosterone or has been taking anabolic steroids and recently quit, the levels of testosterone might be low as well.
This is transient, since external supply of testosterone to the body will reduce its own production. Within a few months after finishing treatment or quitting anabolic steroids, the testosterone levels will normalize.
Elevated levels of testosterone is most often seen in men with an ongoing testosterone treatment. If a man has elevated levels without being treated with testosterone, this may require further investigation. Using anabolic steroids may also increase the levels of testosterone. Elevated testosterone levels often come with potentially harmful changes in cholesterol levels, causing the “bad” cholesterol to increase and the “good” cholesterol to decrease.