A testosterone test checks the level of this male hormone (androgen) in the blood. Testosterone affects sexual features and development. In men, it is made in large amounts by the testicles. In both men and women, testosterone is made in small amounts by the adrenal glands; and, in women, by the ovaries.
WHY SHOULD I HAVE A TESTOSTERONE TEST?
A testosterone test is done to:
- See why a man is having problems in fathering a child (infertility). A low amount of testosterone can lead to low sperm counts.
- Check a man’s sexual problems. A low level of testosterone may lower a man’s sex drive or not allow him to have an erection (erectile dysfunction).
- See whether a high level of testosterone is causing a boy younger than age 10 to have early signs of puberty.
- Check a decreased sex drive in a woman. This may be due to the level of testosterone in her body.
- Find out why a woman is developing male features, such as excessive facial and body hair (hirsutism) and a deep voice.
- Find out why a woman is having irregular menstrual periods.
- See if testosterone-lowering medicines are working in a man with advanced prostate cancer.
- Find the cause of osteoporosis in a man.
Clinical Significance Testosterone circulates almost entirely bound to transport proteins. Normally less than 1% is free. Testosterone measurements are used to assess erectile dysfunction, infertility, gynecomastia, and osteoporosis and to assess hormone replacement therapy.