How It Feels

You may feel nothing at all from the needle puncture, or you may feel a brief sting or pinch as the needle goes through the skin. Some people feel a stinging pain while the needle is in the vein. However, many people do not feel any pain or have only minor discomfort once the needle is positioned in the vein.

Risks

There is very little risk of complications from having blood drawn from a vein.

• You may develop a small bruise at the puncture site. You can reduce the risk of bruising by keeping pressure on the site for several minutes after the needle is withdrawn.
• Rarely, the vein may become inflamed after the blood sample is taken. This condition is called phlebitis and is usually treated with a warm compress applied several times daily.
• Continued bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can also make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your health professional before your blood is drawn.

Results

A follicle-stimulating hormone test measures the amount of follicle-stimulating hormone (FSH) in a blood sample. The test results depend on your age and stage of sexual development.

The phase of a woman's menstrual cycle can affect results, so it is important to know the first day of your last menstrual period at the time the test is performed.

Results are usually available within 24 hours.

Normal

Normal values vary widely among labs and methods used.

Many conditions can change FSH levels.Your health professional will discuss any significant abnormal results with you in relation to your symptoms and medical history.

High values

High FSH values in a woman may indicate:

• Loss of ovarian function before age 40 (ovarian failure).
• Polycystic ovary syndrome (PCOS).
• Menopause has occurred.

High FSH values in a man may indicate:

• Klinefelter syndrome.
• Testicles are absent or not functioning properly.
• Testicles have been damaged by a disease, such as alcohol dependence, or by treatments, such as X-rays or chemotherapy.

High values in children may mean that puberty is about to start.

Low values

Low FSH values may indicate:

• A woman is not producing eggs (prevents ovulation) or a man is not producing sperm.
• An area of the brain (the hypothalamus or pituitary gland) is not functioning properly.
• A tumor is present that interferes with the brain's ability to control FSH production.
• Stress.
• Starvation or being very underweight.