Hormones are chemicals produced by the body to regulate the function of body organs like the heart, blood vessels, bones, muscle and brain. While testosterone is an androgen, or male hormone, it actually regulates sexual function in both men and women. Your body releases the right level of testosterone at the right time to promote the development of gender-specific characteristics like facial and body hair, a deep voice and genitalia.
Where It Comes From
When your testosterone level is too low, your pituitary gland releases a hormone known as luteinizing hormone, or LH. The LH, in turn, triggers the release of testosterone from your adrenal glands. If you're a man, LH also tells your testicles to produce a significant amount of testosterone. If you're a woman, LH signals your ovaries to release lower levels of testosterone.
Indications for Males
According to Lab Tests Online, males may have a blood testosterone level to investigate the cause of delayed or early puberty, erectile dysfunction, diminished sex drive or infertility. Your doctor may also do a testosterone test to rule out medical conditions involving your pituitary gland or testicles.
Indications for Females
If you're female, your physician may order a testosterone level to investigate infertility, disorders of your pituitary gland, menstrual irregularities, excess hair on your body or the development of male sex-related features.
Preparation
You'll need to go to a medical laboratory for a testosterone blood level test, but there's no special preparation before the blood draw. A few days later, your doctor will discuss the results with you.
Normal Male Range
In general, testosterone levels in males are lowest during childhood, peak during adolescence and early adulthood and then drop about 1 percent a year after 30 years of age, according to MayoClinic.com. The University of Michigan Health System says a male infant should have less than 30 nanograms/deciliter, or ng/dL, of testosterone in his blood. From 10 to 13 years of age, a boy should have a testosterone level of 1 to 619 ng/dL. Teens between the ages of 14 and 15 years should run between 8 to 53 ng/dL, while 16- to 19-year-olds average 200 to 970 ng/dL. If you're in your 20s or 30s, you should expect a testosterone level between 270 and 1,080 ng.dL. From 40 to 59 years of age, expect to run between 350 and 890 ng/dL. From 60 years and up, men should have a testosterone level of 350 to 720 ng/dL.
Normal Female Range
Testosterone levels are significantly lower in females than in males, according to the University of Michigan Health System. A female infant should have less than 10 nanograms/deciliter, or ng/dL, in her blood. Between 7 and 9 years of age, the normal level ranges from 1 to 12 ng/dL and from 10 to 13 years of age, a girl should have a testosterone level of 2 to 33 ng/dL. Adolescent girls between the ages of 14 and 17 typically have 8 to 53 ng/dL. Adult women run between 10 and 70 ng/dL before menopause, dropping to 7 to 40 ng/dL after menopause.
