What is the FSH test?

This blood test measures a hormone called follicle stimulating hormone (FSH). This hormone is made by the pituitary gland in your brain. It helps control a woman’s menstrual cycle. It also controls the growth of eggs in the ovaries. In men FSH helps control the production of sperm.

Why is this test done?

The FSH test may help diagnose and check treatment of a medical problem you are having, such as:

• Irregular periods or vaginal bleeding
• Problems getting pregnant
• Sexual development at a very young age or a delay in sexual development
• Some testicle problems, like missing or underdeveloped testicles

An FSH test can also help confirm if a woman is in menopause.

How do I prepare for this test?

• You may need to avoid taking certain medicines before the test because they might affect the test result. Make sure your healthcare provider knows about any medicines, herbs, or supplements that you are taking. Ask your provider before stopping any of your regular medicines.
• In women, the FSH test must be done at certain times during the menstrual cycle. Your healthcare provider will need to know the date of your last menstrual period before scheduling this test.
• Talk to your healthcare provider if you have any questions about the test.

How is the test done?

Having this test will take just a few minutes. A small amount of blood is taken from a vein in your arm with a needle. The blood is collected in tubes and sent to a lab.

Ask your healthcare provider when and how you will get the result of your test.

What does the test result mean?

Females

The FSH level may be higher than normal in women who:

• Are taking hormones
• Have a problem with one or both ovaries, such as polycystic ovary disease, ovarian cysts, or ovarian cancer
• Have adrenal gland problems (the adrenal glands are just above the kidneys and make hormones)
• Have Turner’s syndrome (a genetic problem)
• Are starting menopause

Also, the FSH levels are higher than normal in girls who have started puberty at a very young age.

The FSH level may be lower than normal in women who:

• Have anorexia (an eating disorder)
• Have a problem with the parts of the brain that control hormones (the pituitary gland and hypothalamus)

Males

The FSH level may be higher than normal in men who:

• Are being treated with hormones for a medical condition
• Have Klinefelter’s syndrome (a genetic problem)
• Have a problem with one or both testicles, such as an injury or a tumor

Also, the FSH levels are higher than normal in boys who have started puberty at a very young age.

The FSH level may be lower than normal in men who:

• Have a problem with the parts of the brain that control hormones (the pituitary gland and hypothalamus)

There are many other reasons why FSH test results may be outside the normal range. Sometimes the results vary with recent activity or diet. At other times the way the sample is collected or stored can affect the results.

Other hormone tests may be done with the FSH test. The results of the different tests need to be interpreted together to make a diagnosis.

What if my test result is not normal?

Test results are only one part of a larger picture that takes into account your medical history, physical exam, and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about your result and ask questions, such as:

• If you need more tests
• What kind of treatment you might need
• What lifestyle, diet, or other changes you might need to make