Testosterone Levels in Teenagers

by Beth Greenwood

    Hormones influence many body systems, human growth and development. Two major hormones are testosterone and estrogen. Testosterone is often called a “male” hormone, even though both males and females secrete testosterone as well as estrogen. The difference lies in the amounts. Boys and men secrete more testosterone while women and girls secrete more estrogen. The two hormones work together to maintain overall health.

    Testosterone is secreted by the adrenal glands in both boys and girls, as well as by the ovaries in girls and the testes in boys. During puberty, boys begin to secrete higher amounts of testosterone, which leads to the development of characteristics such as a deeper voice, a beard, hair on the chest, underarms and genitals, and increased muscle mass. Girls, on the other hand, respond to increased estrogen during puberty by developing breasts and fat in areas such as the abdomen, hips and buttocks. Teens of both sexes, however, should continue to secrete testosterone despite the changes of puberty.

    Blood tests can check for testosterone levels. The test usually consists of two parts -- a total testosterone and a free testosterone. The total testosterone measures the entire amount of testosterone in the body, while free testosterone measures the testosterone not attached to proteins. Testosterone levels that are too high or too low can signal problems with various parts of the hormonal system. For example, the pituitary gland in the brain secretes two different hormones that regulate the manufacture of testosterone. A low testosterone level may mean there is a problem with the pituitary. Normal testosterone levels vary among individuals, but the range for males is 300 to 1,000 ng/dL -- or nanograms per deciliter -- and the normal range for females is 15 to 70 ng/dL, according to MedlinePlus.

    Hormonal balance is important for all hormones, and that includes testosterone. MedlinePlus says high levels of testosterone in teen boys can be a sign of early puberty, tumors of the testicles or hyperthyroidism -- a high level of thyroid hormone in the blood. High testosterone may also indicate that the teen is using steroids, also called androgens or anabolic steroids. Since testosterone is normally low in teen girls, a high level usually means there is a problem. Teen girls with high testosterone levels might also be using steroids, or could have polycystic ovarian syndrome or a tumor of the ovary or the adrenal gland. Drugs such as anticonvulsants -- drugs given for seizure disorders -- or sleeping pills called barbiturates can increase testosterone levels.

    Abnormally low testosterone, especially in teen boys, often means a health problem, as healthy teen boys usually have testosterone levels in the high end of the range. Alcoholism can cause a decreased testosterone level in males. Genetic diseases can cause a low testosterone in males and diseases of the pituitary gland can cause low testosterone in boys and girls. Physical injury to the testes or viral diseases such as mumps can also decrease testosterone levels in boys by impairing production. According to a March 2013 article in “Clinical Endocrinology,” teen boys who were obese at the time of the test had testosterone levels as much as 40 to 50 percent lower than boys of normal weight.

    About the Author

    Beth Greenwood is a registered nurse and writer. She served as a columnist for the Tides Foundation's Community Clinic Voice on quality improvement and now contributes to various websites. Greenwood holds an Associate of Science in nursing from Shasta College and is a graduate of the California HealthCare Foundation Health Care Leadership Program.

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