Testosterone, Serum or Plasma Mass Concentration

Your doctor may order this test to help diagnose a medical condition, check how well a treatment is working, or screen for health problems before symptoms appear. It can also be used to monitor an ongoing condition or to look into symptoms such as pain, fatigue, or abnormal findings from earlier tests.

Your healthcare provider may recommend this test if you have symptoms like low energy, reduced sex drive, or issues with fertility. It could also be part of evaluations for conditions like hypogonadism (low testosterone), polycystic ovary syndrome (PCOS), or other hormonal disorders. Men and women may be tested for different reasons, such as evaluating fertility, diagnosing hormonal imbalances, or monitoring treatment responses.

Before your test, your care team will explain the procedure and give you specific instructions to follow. You may need to avoid certain foods, drinks, or medications for a period of time beforehand. Be sure to tell your provider about any allergies, medical conditions, or medicines you take, including supplements and over-the-counter drugs.

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it involves a blood draw. Avoid smoking or consuming alcohol for at least 24 hours beforehand. If you are on hormone therapy, let your provider know to avoid interfering with results.

During the test, a trained healthcare professional will perform the procedure in a clinic, hospital, or laboratory setting. Depending on the type of test, this may involve providing a small sample of blood, urine, or other tissue, or using imaging equipment. Most tests take only a short time, and you can usually go home the same day.

A healthcare professional will draw blood from a vein in your arm. The blood sample is then sent to a lab for analysis. The test measures testosterone levels in your serum or plasma, depending on the lab’s method.

Your results will show whether your values fall within the normal range for this test. Abnormal results do not always mean you have a serious condition, and your doctor will interpret them together with your symptoms, medical history, and other test findings. Your provider will contact you to discuss what the results mean and what steps, if any, come next.

Results are compared to reference ranges specific to your sex and age. Low testosterone may indicate conditions like hypogonadism, while very high levels could signal tumors or other health issues. Your provider will interpret results in the context of your symptoms and medical history.