Continued
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
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.
| Menstruating women | |
|---|---|
|
Follicular phase: |
1.37-9.9 international units per liter (IU/L) |
|
Midcycle peak: |
6.17-17.2 IU/L |
|
Luteal phase: |
1.09-9.2 IU/L |
| Women past menopause: |
19.3-100.6 IU/L |
| Men: |
1.42-15.4 IU/L |
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 values
High FSH values in a woman may mean:
- Loss of ovarian function before age 40 (ovarian failure).
- Menopause has occurred.
High FSH values in a man may mean:
- 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 mean:
- 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.
What Affects the Test
Results of the follicle-stimulating hormone (FSH) test may be affected by:
- The use of hormones, such as testosterone, estrogen, and progesterone (including birth control pills).
- Heavy cigarette smoking.
- Age.
- The use of medicines, such as cimetidine, clomiphene, digitalis, and levodopa. 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.
- Having a test such as a thyroid scan or bone scan that uses a radioactive substance within 1 week of the FSH test.