TESTOSTERONE

Testosterone is a sex hormone that plays an important role in puberty.

In men, testosterone not only regulates the sex drive (libido), it also helps regulate bone mass, fat distribution, muscle mass and strength, and the production of red blood cells and sperm. In men, testosterone is produced in the testes, the reproductive glands that also produce sperm.

The amount of testosterone produced in the testes is regulated by the hypothalamus and the pituitary gland. You may want this test to assess your testosterone levels which may help to explain difficulty getting an erection, if your partner is unable to get pregnant (infertility) or if you have premature or delayed puberty if you are male. Women produce small amounts of it in their bodies as well.

If you are female you may wish to account for masculine physical features.

Testosterone testing is used to diagnose several conditions in men, women, and boys. These conditions include:

delayed or precocious (early) puberty (boys);
decreased sex drive (men);
erectile dysfunction (men);
infertility (men and women);
testicular tumours (men); and
excessive body hair, also called hirsutism, and masculinisation, also called virilisation (women).

Alcoholism and liver disease in males can decrease testosterone levels. Drugs, including androgens and steroids, can also decrease testosterone levels. Prostate cancer responds to androgens, so many men with advanced prostate cancer receive drugs that lower testosterone levels.

Women taking oestrogen therapy may have increased testosterone levels.

Anticonvulsants, barbiturates, and clomiphene can cause testosterone levels to rise.