Definition

The follicle stimulating hormone (FSH) blood test measures the level of FSH in blood. FSH is a hormone released by the pituitary gland, located on the underside of the brain.

Alternative Names

Follicle stimulating hormone; Menopause – FSH; Vaginal bleeding – FSH

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

If you are a woman of childbearing age, your health care provider may want you to have the test done on certain days of your menstrual cycle.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

In women, FSH helps manage the menstrual cycle and stimulates the ovaries to produce eggs. The test is used to help diagnose or evaluate:

• Menopause
• Women who have polycystic ovary syndrome, ovarian cysts
• Abnormal vaginal or menstrual bleeding
• Problems becoming pregnant, or infertility

In men, FSH stimulates production of sperm. The test is used to help diagnose or evaluate:

• Problems becoming pregnant, or infertility
• Men who do not have testicles or whose testicles are underdeveloped

In children, FSH is involved with the development of sexual features. The test is ordered for children:

• Who develop sexual features at a very young age
• Who are delayed in starting puberty