Both men and women make testosterone in their bodies, although men usually produce much more of it than women. A blood test for testosterone can show how much of this important sex hormone is in your body.
What is being tested?
Testosterone is the main sex hormone produced in men. It helps make sperm, and it influences men's sex drive. It also helps create facial and body hair, and plays a part in the development of muscles. Men make testosterone mainly in their testes, but also in their adrenal glands.
Women make a much smaller amount in their ovaries, adrenal glands and other body tissues. Some of this breaks down to form a type of oestrogen called oestradiol.
Some testosterone is found in the blood both of men and women. A blood test for testosterone will show how much is in your body.
Why would I need this test?
Your doctor might suggest a blood test for testosterone if:
- you are having problems conceiving a child – both men and women can be tested
- you are a man with a low sex drive
- you are a man with problems getting an erection
- you are a woman with masculine features, such as a lot of body hair or a low voice
- you are a boy and puberty has come very early, or is very late
Some diseases can also affect the amount of testosterone in your blood. These include diabetes, mumps, and tumours on the testicles or ovaries. People who drink too much alcohol can also have low testosterone levels.
How to prepare for the test
You might be asked to have a fasting test early in the morning. In that case, you should stop eating by midnight, then only have sips of water in the morning. You can usually continue to take any medications you need, but check with your doctor.
Understanding your results
Many things can affect your testosterone blood test results, including your age, your health, and what’s happening with your body.
You will need to discuss the results with your doctor, what they mean, and what comes next.
- Read the healthdirect Guide to blood testing
- Lab Tests Online has more information on blood tests in general and testosterone in particular
- myVMC has more information about testosterone
- Pregnancy Birth and Baby has more information on blood tests during pregnancy
- Healthdirect's Question Builder can help you prepare for a doctor's appointment
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Last reviewed: May 2018