A testosterone test is a blood test that measures testosterone levels, a hormone crucial for male sexual development and function, but also important in women for hormonal balance. The test is ordered by a doctor to diagnose conditions like hypogonadism, infertility, erectile dysfunction, or premature puberty in boys, and to investigate symptoms like excess facial hair in women. Blood is drawn, preferably in the morning when levels are highest, and analyzed in a lab. [1, 2, 3, 4, 5, 6]
Why the test is done
Doctors recommend a testosterone test to investigate a range of symptoms and conditions in both men and women: [1, 3, 4, 7, 8]

• In men: Low sex drive, erectile dysfunction, infertility, osteoporosis.
• In women: Irregular periods, male-pattern hair growth (hirsutism), deep voice.
• In boys: Delayed or early puberty.

How the test is performed

1. Blood Sample: A healthcare provider, such as a phlebotomist, will draw a small blood sample, usually from a vein in your arm. [6, 9]
2. Timing: The sample is ideally collected in the morning, between 7 a.m. and 10 a.m., when testosterone levels are naturally highest. [5, 10]
3. Laboratory Analysis: The collected blood is sent to a laboratory to measure your total testosterone levels. [6]
4. Results: The results indicate whether your testosterone levels are normal, high, or low, and are interpreted in the context of your sex and age. [2, 11]

Preparation and Risks

• Preparation: You may need to avoid eating or drinking for a few hours before the test (fasting), so it's important to ask your doctor for specific instructions. [5, 10]
• Risks: A testosterone blood test is a very common procedure with minimal risks. You might experience a brief pinch from the needle and a small bruise or tenderness at the puncture site, which typically resolves quickly.