Testosterone is the main sex hormone in males. During a boy’s puberty, testosterone causes the growth of body hair, muscle development, and deepening of the voice. In adult men, it controls sex drive, maintains muscle mass, and helps make sperm. Women also have testosterone in their bodies, but in much smaller amounts. This test measures the levels of testosterone in your blood. Most of the testosterone in the blood is attached to proteins. Testosterone that is not attached to a protein is called free testosterone.
There are two main types of testosterone tests:
Testosterone levels that are too low (low T) or too high (high T) can cause health problems in both men and women. Other names: serum testosterone, total testosterone, free testosterone, bioavailable testosterone
A testosterone levels test may be used to diagnose several conditions, including: Decreased sex drive in men and women Infertility in men and women Erectile dysfunction in men Tumors of testicles in men Early or delayed puberty in boys Excess body hair growth and development of masculine features in women Irregular menstrual periods in women.
You may need this test if you have symptoms of abnormal testosterone levels. For adult men, it’s mostly ordered if there are symptoms of low T levels. For women, it’s mostly ordered if there are symptoms of high T levels.
Symptoms of low T levels in men include:
Symptoms of high T levels in women include:
Boys may also need a testosterone levels test. In boys, delayed puberty can be a symptom of low T , while early puberty may be a symptom of high T.