The amounts of FSH and other hormones (luteinizing hormone, estrogen, and progesterone) are measured in both a man and a woman to determine why the couple can't become pregnant (infertility). The FSH level can help determine whether male or female sex organs (testicles or ovaries) are functioning properly.
Why It Is Done
A follicle-stimulating hormone (FSH) test may be done to:
How To Prepare
Many medicines, such as cimetidine, clomiphene, digitalis, and levodopa, can change your test results. You may be asked to stop taking medicines (including birth control pills) that contain estrogen or progesterone or both for up to 4 weeks before having a follicle-stimulating hormone (FSH) test. Make sure your doctor has a complete list of all the prescription and over-the-counter medicines you are taking, including herbs and natural substances.
Tell your doctor if you have had a test that used a radioactive substance (tracer) within the last 7 days. Recent tests using a radioactive tracer (such as a thyroid scan or bone scan) can interfere with FSH test results.
Let your doctor know the first day of your last menstrual period. If your bleeding pattern is light or begins with spotting, the first day is the day of heaviest bleeding.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
The health professional drawing your blood will:
For a woman who is having problems with her menstrual cycle or who cannot become pregnant, more than one blood sample may be needed to help identify a follicle-stimulating hormone (FSH) problem. A sample may be taken each day for several days in a row.
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. But many people do not feel any pain or have only minor discomfort once the needle is positioned in the vein.
There is very little risk of complications from having blood drawn from a vein.
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.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Many conditions can change FSH levels. Your doctor will discuss any significant abnormal results with you in relation to your symptoms and past health.
High FSH values in a woman may mean:
High FSH values in a man may mean:
High values in children may mean that puberty is about to start.
Low FSH values may mean:
What Affects the Test
Results of the follicle-stimulating hormone (FSH) test may be affected by:
What To Think About
If you are taking a medicine that contains testosterone, estrogen, or progesterone (such as birth control pills), ask your doctor whether you should stop taking it for several days before having a follicle-stimulating hormone (FSH) test.
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