FSH stands for follicle-stimulating hormone (FSH). This hormone is released by the anterior pituitary gland.

In women, FSH stimulates production of eggs and a hormone called estradiol during the first half of the menstrual cycle.

In men, FSH stimulates production of sperm.

This article discusses the test to check the level of FSH in the blood.

Your doctor may order this test if you have signs of certain reproductive or pituitary disorders. In some situations, it may also be done to confirm menopause.

The FSH test is usually done to help diagnose problems with sexual development, menstruation, and fertility. The test is used to help diagnose or evaluate:

• Menopause
• Women who have polycystic ovary disease, ovarian cysts, irregular vaginal bleeding, or infertility
• Children who start sexual development at a very young age
• Men who have infertility
• Men who do not have testicles or whose testicles are underdeveloped

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

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

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.