Testosterone, Total

What is testosterone?

Testosterone is a hormone that is found in both genders. In men, it is responsible for controlling sex drive, regulating sperm formation, promoting muscle mass and increasing energy. Human behavior can also be affected by the levels of this hormone. In men, this hormone is essential in the development of the male reproductive system as well as masculine traits. Low levels of this hormone in men may lead to low libido, erectile dysfunctions, infertility, impotence and few erections.

In women, testosterone is found at low levels and in charge of normal body functions. When levels of this hormone are high in women, she starts experiencing acne, irregular menstruations, absence of periods, loss of scalp hair, growth of facial hair, and infertility. Low levels in women may lead to infertility, loss of libido and weak bones.

Testosterone is found in two forms. The vast majority of this hormone is bound to a protein, while only 2% is found free and biologically available. This test measures both forms of testosterone.

Why take the total testosterone test?

The total testosterone test is a great tool to diagnose abnormal testosterone levels in men and women. In men, it can help identify the causes for erectile dysfunctions and infertility. In women, it helps diagnose the cause behind the development of masculine traits, infertility or polycystic ovary syndrome. Young boys and girls can benefit from this test to identify the cause behind ambiguous genitalia and delayed or early puberty.

What causes the levels of total Testosterone levels to rise?

Alcohol, liver disease and the use of androgens like testosterone and steroids can change your levels of testosterone hormone. Such abnormal results can lead to misdiagnosis and medical errors. It could even lead to unnecessary tests. Men who are being treated for prostate cancer may show abnormal levels of testosterone due to the medication prescribed.

What your total testosterone test results mean?

Levels of total testosterone differ between genders and age groups. Values are referenced according to tanner stages. Professor James Tanner who is a child development expert identified the visible stages of puberty. These are called the tanner stages; and, they refer to the sexual maturity ratings. They are a guide that explains the physical development of boys and girls during puberty. For tanner stage one, girls are normally 8 years old and boys 9-10 years. For tanner stage 2, girls are normally between the ages of 9 and 11 years while boys are 11 years old. For tanner stage 3, girls are normally around 12 years of age and boys 13. For tanner stage 4, girls are normally 13 years old while boys are 14. Finally, for tanner stage 5, girls and boys are around the age of 15 at the beginning of this phase.

The testosterone test has to be done in the morning since it is the time when the testosterone levels are at their highest. Before a diagnosis is confirmed, the test may be repeated.

For boys and men, total testosterone levels are less than 3 ng/dL for Tanner stage I, between 0 and 432 ng/dL for Tanner stage II, between 65 and 778 ng/dL for Tanner stage III, between 180 and 763 ng/dL for Tanner Stage IV, and between 188 and 882 ng/dL for Tanner stage V. For adults who are older than 18 years, total testosterone levels are expected to be between 264 and 916 ng/dL.

For girls and women, total testosterone levels are less than 3-6 ng/dL for Tanner stage I, between 0 and 10 ng/dL for Tanner stage II, between 0 and 24 ng/dL for Tanner stage III, between 0 and 27 ng/dL for Tanner Stage IV, and between 5 and 38 ng/dL for Tanner stage V. For adults who are between ages 20 and 49 years, total testosterone levels are expected to be between 8 and 48 ng/dL; and between 3 and 41 ng/dL for women who are older than 49 years.

If your levels of testosterone are lower than the normal ranges, may be caused by a hypothalamic condition or a pituitary disease. Some genetic illnesses may lead to lower-than-normal levels, including Klinefelter, Kallman, and Prader-Willi syndrome. Other causes include infertility, testicular failure, myotonic dystrophy, diabetes, or viral conditions like mumps.

Higher than normal levels may indicate testicular tumors, adrenal tumors, the use of androgens, and congenital adrenal hyperplasia in young boys. In women, higher levels may indicate PCOS, ovarian cancer, adrenal gland tumor or congenital adrenal hyperplasia.

Where can I get a total testosterone test near me?

Please use our Lab Locator to find find a convenient testing location.

Reviewed By: Dr. Kurt Kloss, MD
Last Reviewed Date: Aug 30, 2019