How is it used?
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)
- excessive body hair, also called hirsutism (women)
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When is it requested?
In boys, the test is performed with the
FSH and
LH tests, if puberty is delayed or slow in developing. Although puberty begins at different times in different individuals, generally by the age of 10 years, there are hormonal and physical manifestations of the onset of puberty. A delay can occur if the testes do not produce enough testosterone or if the pituitary does not produce enough LH.
The test may be performed if a young boy seems to be undergoing a very early (precocious) puberty with obvious secondary sex characteristics, such as an enlarged penis, development of muscle mass and growth of body hair.
In men, the test may be performed when infertility is suspected or if the patient has a decreased sex drive or erectile dysfunction, which can result from low testosterone levels.
In women, testosterone may be measured if a patient has irregular or no menstrual periods, is having difficulty getting pregnant, or appears to have masculine features, such as facial and body hair, male pattern baldness and a low voice. Testosterone levels can rise because of that develop in either the ovary or adrenal gland or because of other conditions, such as polycystic ovarian syndrome (PCOS).
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What does the test result mean?
There is great variability in testosterone levels between men and it is normal for testosterone levels to decline as men get older.
However, in males, a decreased testosterone level may indicate hypothalamic or pituitary disease with reduced secretion of LH and FSH, or damage to the testes with reduced production of testosterone. Genetic diseases also can cause decreased testosterone production in young men (Klinefelter’s, Kallman’s, and Prader-Willi syndromes) or testicular failure and infertility (as in myotonic dystrophy, a form of muscular dystrophy). A decreased testosterone level also can indicate impaired testosterone production because of acquired damage to the testes, such as alcoholism, physical injury or viral diseases like mumps.
Increased testosterone levels in males can indicate testicular tumours or use of androgens (also called anabolic steroids). Increased testosterone in boys is usually the cause of early puberty.
In women, increased testosterone levels can indicate polycystic ovary syndrome (PCOS) or an ovarian or adrenal gland tumour.
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Is there anything else I should know?
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.
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