Total testosterone

Total testosterone is a blood test that measures the amount of testosterone, a vital hormone in both men and women, in the bloodstream. This test is often used to diagnose hypogonadism, polycystic ovary syndrome, and other endocrine disorders.

Overview

Testosterone is a steroid hormone produced primarily in the testes in men and the ovaries in women, although small amounts are also produced by the adrenal glands. It plays a key role in the development of male reproductive tissues such as the testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair. In addition, testosterone is involved in health and well-being, and the prevention of osteoporosis.

Test Procedure

The total testosterone test is a simple blood test. The blood sample is usually taken from a vein in the arm. The test is typically performed in the morning, when testosterone levels are highest. The blood sample is then sent to a laboratory for analysis.

Interpretation of Results

Testosterone levels are measured in nanograms per deciliter (ng/dL). The normal range for total testosterone is typically 300 to 1,000 ng/dL in men and 15 to 70 ng/dL in women. Levels below or above the normal range may indicate an endocrine disorder.

Conditions Related to Abnormal Total Testosterone Levels

Low total testosterone levels in men, a condition known as hypogonadism, can lead to symptoms such as fatigue, low sex drive, and mood changes. In women, high total testosterone levels can indicate polycystic ovary syndrome (PCOS), a condition characterized by irregular or absent menstrual periods, acne, and excessive hair growth.

See Also

• Free testosterone
• Bioavailable testosterone
• Hormone replacement therapy
• Endocrinology