Testosterone Test
A blood test that measures testosterone, a hormone found in both males and females (in smaller amounts in females) that helps control sex drive and supports muscle and bone growth.
Testosterone Test
A blood test that measures testosterone, a hormone found in both males and females (in smaller amounts in females) that helps control sex drive and supports muscle and bone growth.
Also known as
- Total testosterone
What it measures
- Total testosterone (bound and unbound) — the most common version
- Sometimes free or bioavailable testosterone
Why a doctor may order it
In males who have gone through puberty it is mostly used when symptoms could go with low testosterone — such as low sex drive, difficulty getting or keeping an erection, infertility, loss of muscle mass, or thinning bones or anaemia with no known cause. In females it is mostly used for symptoms that could go with high testosterone, such as abnormal hair growth on the face or body.
What it helps evaluate
It can help a doctor look for the cause of abnormal testosterone levels, or monitor you if you take hormone therapy or medicines that affect testosterone. It does not diagnose a condition on its own.
Preparation
In some cases you may need to fast for several hours or stop certain medicines. Tell your provider about everything you take, and do not stop any medicine unless told to.
Fasting
Fasting is sometimes needed. Follow the instructions you are given.
Important considerations
- What is considered typical differs by sex and by age.
- Different versions of the test exist (total, free, bioavailable); total testosterone is the most common.
Discuss results with your doctor
Talk to a doctor about your symptoms and about what your results mean — a single result is not a diagnosis. See a doctor promptly for severe or worsening symptoms.