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
pituitary gland controls the level of testosterone in
the body. When the testosterone level is low, the pituitary gland releases a
luteinizing hormone (LH). This hormone tells the
testicles to make more testosterone.
puberty, the testosterone level in boys is normally
low. Testosterone increases during puberty. This causes boys to develop a
deeper voice, get bigger muscles, make
sperm, and get facial and body hair. The level of
testosterone is the highest around age 40, then gradually becomes less in older
In women, the ovaries account for half of the testosterone in
the body. Women have a much smaller amount of testosterone in their bodies
compared to men. But testosterone plays an important role throughout the body
in both men and women. It affects the brain, bone and muscle mass, fat
distribution, the vascular system, energy levels, genital tissues, and sexual
Most of the testosterone in the blood is bound to a
protein called sex hormone binding globulin (SHBG). Testosterone that is not
bound ("free" testosterone) may be checked if a man or a woman is having sexual
problems. Free testosterone also may be tested
for a person who has a condition that can change SHBG levels, such as hyperthyroidism or some types of kidney diseases.
Total testosterone levels vary throughout the day. They are usually highest in the morning and lowest in the evening.
testosterone test is done to:
You do not need to do anything before
you have this test. Your doctor may want you to do a morning blood test because
testosterone levels are highest between 7 a.m. and 9 a.m.
The health professional taking a sample
of blood will:
The blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or
There is very little chance of a problem from
having a blood sample taken from a vein.
testosterone test checks the level of this male
hormone (androgen) in the blood.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Your doctor will have your test results in a few days.
270–1070 ng/dL (9–38 nmol/L)
15–70 ng/dL (0.52–2.4 nmol/L)
Children (depends on sex and age at puberty)
2–20 ng/dL or 0.07–0.7 nmol/L
The testosterone level for a postmenopausal woman is
about half the normal level for a healthy, nonpregnant woman. And a pregnant
woman will have 3 to 4 times the amount of testosterone compared to a healthy,
50–210 pg/mL (174–729 pmol/L)
Reasons you may not be able to
have the test or why the results may not be helpful include:
To learn more, see:
CitationsFischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.Other Works ConsultedChernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
May 17, 2012
E. Gregory Thompson, MD - Internal Medicine & Alan C. Dalkin, MD - Endocrinology
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