Testosterone is a male hormone that causes body hair and muscle growth in men, regulates sex drive, builds bone mass, maintains healthy organs and muscles, and helps produce sperm. A low level can be caused by certain health conditions or medicines. A blood sample is needed for this test. You may feel a slight prick or sting when the needle is inserted.

What Is Testosterone?

Testosterone is a hormone made in your gonads (sex organs) and, in women, in your ovaries. This androgen hormone mainly stimulates the development of secondary male characteristics during puberty such as body hair and a deep voice, and it is essential for producing sperm. It also plays an important role in the production of red blood cells and muscle mass.

Testosterone levels decrease with age in men. Low testosterone is also a characteristic of some diseases and health conditions, including diabetes and high blood pressure.

A test to check your total testosterone level measures both free and bound forms of the hormone. Most of the testosterone in your body is attached to proteins. The test is usually done in the morning before you eat, although your doctor may tell you to skip eating for a few hours before your test. Some tests measure only the amount of unbound, or "free," testosterone in your body. These results are less common but can be useful in some situations.

Why Is Testosterone Tested?

A testosterone blood test measures the levels of this male sex hormone in your body. It’s important for many reasons, including regulating sex drive, building bone mass, determining body fat distribution, and maintaining muscle mass and strength. It is also essential for sperm production.

Testosterone levels decrease with age. This is a normal process, but it can lead to low testosterone (Low-T) in some men.

You may need to fast for several hours before the test. This means not eating anything except for a few sips of water. Check with your pathology collection centre or doctor about this.

Most tests use a finger-prick blood sample. They draw a drop of blood with a spring-loaded cutting device called a lancet. Choose a finger on your non-dominant hand and clean it with an alcohol swab. Generally, these tests are best done in the morning before 10 a.m. Blood is collected on a collection card that’s covered in circles.

How Is Testosterone Tested?

Generally, most tests for testosterone require a blood sample. These tests are typically finger-prick tests that use a spring-loaded cutting device (lancet) to draw a drop of blood from the tip of your finger. You may be asked to avoid eating or drinking anything (except water) for several hours before your test.

Hair samples can also be tested for testosterone. In this test, the immunoreactivity of methanol extracts from a lock of hair is measured using an in-house competitive radioimmunoassay. Testosterone levels are typically highest in the morning.

During male puberty, testosterone builds a man’s muscles, makes his penis grow, and deepens his voice. In adulthood, it controls sex drive and maintains muscle mass. Women have testosterone in small amounts, but it helps make sperm and keeps their organs healthy. This test can find conditions caused by too little or too much testosterone, such as polycystic ovary syndrome (PCOS). Testosterone levels also decline naturally with age.

What Does the Testosterone Test Measure?

The test measures the amount of testosterone in the blood. It may help doctors find out the cause of problems like decreased sex drive or erectile dysfunction in men. It can also help them see whether a boy younger than 10 is going through puberty early (precocious). And it can help doctors find out why a woman is getting male patterns of hair growth (hirsutism) or having irregular periods.

Doctors often use a total testosterone test, which looks at both the free and attached form of testosterone. They may also order a test that only measures the free form of the hormone.

Some tests are best done when a person is fasting. This means not eating or drinking anything but water for about 12 hours before the test. Ask your doctor or the pathology collection centre about what to do before a test. Also, some medicines like antifungals and hormone medicines might affect the test results.