Description:

Also known as: Total testosterone
Related tests: Follicle stimulating hormone (FSH), luteneizing hormone (LH), Sex hormone binding globulin (SHBG), Free and bioavailable testosterone (see FAQ section)
Why get tested?
To determine if your testosterone level is abnormal, which may help to explain difficulty getting an erection (erectile dysfunction), inability of your partner to get pregnant (infertility), or premature or delayed puberty if you are male, or the appearance of masculine physical features if you are female

When to get tested?
If you are male and your doctor thinks that you may be infertile or if you are unable to get or maintain an erection; if you are a boy with either early or delayed sexual maturity; if you are a female but have male traits, such as a low voice or excessive body hair, or are infertile
What is being tested?
Testosterone is a steroid hormone (androgen) made by the testes in males. Its production is stimulated and controlled by luteinizing hormone (LH), which is manufactured in the pituitary gland. In males, testosterone stimulates development of secondary sex characteristics, including enlargement of the penis, growth of body hair and muscle, and a deepening voice. It is present in large amounts in males during puberty and in adult males to regulate the sex drive and maintain muscle mass. Testosterone is also produced by the adrenal glands in both males and females and, in small amounts, by the ovaries in females. In women, testosterone is converted to estradiol, the main sex hormone in females