How to Determine Low or High FSH Levels may earn compensation through affiliate links in this story.

The FSH test is a measurement of levels of the follicle-stimulating hormone, which is often done along with other tests to try to determine the cause of infertility. It can help diagnose the cause of low sperm count as well as determine the source of irregularities in the menstrual cycle. This test can also be done for children in order to determine the cause of delayed or absent puberty.

Step 1

Get your blood tested. FSH levels are commonly assayed using a blood test that your physician (or an endocrinologist, who specializes in hormones) can order. He will draw a blood sample for this test, which can be done during an appointment.

Step 2

Come to your follow-up appointment. During your follow-up visit, your physician will be able to present your results and discuss what they may mean.

Step 3

Compare your results to reference ranges. FSH hormone levels are typically reported back in mIU per milliliter, which is the standard unit for these types of hormone assays. For men, FSH levels should be between 4.6mIU and 12.4mIU per milliliter. Women's FSH levels will vary depending on what stage of the menstrual cycle they are in when the blood sample has been taken. For women in the follicular phase of the menstrual cycle, their FSH should be between 6.9mIU and 12.5mIU per milliliter. Women in the ovulation phase should have FSH levels between 12.3 and 21.5. Women in the luteal phase should have levels between 3.6 and 7.7. Women in menopause should have their FSH levels between 67.0 and 134.8.

Step 4

Be aware of what can cause low FSH levels. In men and women, low FSH levels are typically indicative of a problem with the hypothalamus or the pituitary gland. These two organs secrete hormones that can affect the ovaries (in women) or testicles (in men).

Step 5

Learn about what causes high FSH levels. Elevated FSH levels are usually a result of failure of the ovaries or testicles. In men, it can be the result of a genetic abnormality, a failure of the testes to develop, or damage to the testicles (which could result from radiation, a mumps infection, trauma or other causes). In women, FSH levels can be elevated due to a genetic defect, a failure of the ovaries to develop or produce hormones, as well as ovarian failure (in which the ovaries fail to develop due to an auto-immune disease, chemotherapy, or radiation) or from a failure to ovulate (which can be caused by thyroid problems, a tumor or a condition known as polycystic ovarian syndrome).

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