Total serum testosterone
Testing testosterone is not only for men. Testing testosterone levels is also very important in females.
Total serum testosterone Overview
Although testosterone is the most important male sex hormone, both men and women produce this hormone. In males, the testicles produce most of the testosterone in the body. Levels are most often checked to evaluate signs of low testosterone.
In females, the ovaries produce most of the testosterone. Levels are most often checked to evaluate signs of higher testosterone levels.
Testosterone is measured in nanograms per deciliter (ng/dL). The normal ranges for testosterone are the following:
- Male: 300 to 1000 ng/dL
- Female: < 62 ng/dL
Fasting is not required before the test.
Levels should be drawn at 7 AM, when the levels are the highest.
What the results mean
Elevated testosterone levels may result from androgen-secreting tumors of the adrenal gland, late-onset congenital adrenal hyperplasia, or Cushing syndrome. In women, elevated serum testosterone levels can be due to androgen-secreting tumors of the adrenal gland or ovary (>150 ng/dL) or PCOS. In adolescent males and females, elevated testosterone levels may indicate of precocious puberty.
In boys, a decreased testosterone concentration may be indicative of hypogonadism. In men, decreased testosterone levels may be due to primary testicular failure, secondary or tertiary hypogonadism, or treatment of prostate cancer with certain medications.