Normal Testosterone Level

Testosterone is a hormone found in men and women. In both sexes, this hormone is involved in sex drive, muscle mass and bone density. Additionally in men, testosterone is plays a role in sperm production and red blood cell production.

Testing in Men

• A testosterone level is used to evaluate delayed or early puberty in boys and infertility, impotence or to diagnose testicular cancer in men.

Testing in Women

• This level is obtained in women to evaluate the presence of male characteristics, irregular menstrual periods and to diagnose ovarian cancer.

Normal Levels

• According to MedlinePlus.com, a normal testosterone level for an adult male is 300 to 1,000 nanograms per deciliter and for an adult female is 20 to 80 nanograms per deciliter. Your physician will decide if your testosterone level is abnormal.

Increased Levels in Men

• Increased levels of testosterone in men may indicate pinealoma, encephalitis, congenital adrenal hyperplasia, hyperthyroidism, testosterone resistance syndromes and andrenocortical, testicular or extragonadal tumors.

Increased Levels in Women

• Increased levels of testosterone in females may indicate congenital andrenocortical hyperplasia, polycystic ovaries, idiopathic hirsutism and ovarian, adrenal or trophoblastic tumors.

Decreased Levels

• In men, decreased levels of testosterone may signify Klinefelter's syndrome, cryptorchidism, hypogonadism, Down syndrome, hepatic cirrhosis and orchidectomy.