How to Interpret an FSH Test

Updated July 20, 2017

A FSH test measures the amount of follicle stimulating hormone (FSH) circulating in the blood. This test helps diagnose fertility, sexual maturation and menstrual problems. A FSH test may be ordered by your doctor if you are a woman experiencing infertility, polycystic ovary syndrome (PCOS), ovarian cysts or irregular vaginal bleeding. It can also indicate if a woman has reached menopause. Men who are infertile, or who have no testicles or undeveloped testicles and children with premature sexual development may also have the FSH test.

Compare your FSH level with the lab's reference ranges on the test results. Reference ranges differ among labs. Normal readings vary according to sex and age. Average normal readings for males before entering puberty are 0 to 5.0 mIU/ml (milli international units per millimetre), during puberty 0.3 to 10.0 mIU/ml and as adults 1.5 to 12.4 mIU/ml. Average readings for females before entering puberty are 0 to 4.0 mIU/ml, during puberty 0.3 to 10.0 mIU/ml, or when menstruating, are 4.7 to 21.5 mIU/ml. Women who are post-menopausal receive 25.8 to 134.8 mIU/ml.

Determine if your FSH levels are higher than normal. If you are female, possible causes of high FSH levels include being in or past menopause, ovarian cancer, adrenal cancer, Turner's syndrome (a genetic condition), hormone therapy, premature sexual development in girls and drugs that induce ovulation. Levels over 12 mIU/ml in females of child-bearing age may indicate impaired ovarian reserve, and FSH levels over 25 mIU/ml may indicate ovarian failure. If you are male, possible causes of high FSH levels include undergoing hormone treatments for a medical condition, Klinefelter's syndrome (a genetic condition), testicle removal, male menopause and premature sexual development in boys.

Determine if you FSH levels are lower than normal. If you are female, possible causes of low FSH levels include the use of birth control pills, pregnancy, anorexia nervosa, pituitary problems and hypothalamus problems. If you are male, possible causes include the pituitary not producing enough hormones and hypothalamus problems.

Discuss your personal FSH test results with your doctor. Other tests are often given along with the FSH test to provide an accurate diagnosis. Results sometimes vary with activity, diet, time of day and sample collection procedures.

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About the Author

Annette Strauch has been a writer for more than 30 years. She has been a radio news journalist and announcer, movie reviewer for Family Movie Reviews Online, chiropractic assistant and medical writer. Strauch holds a Master of Arts in speech/broadcast journalism from Bob Jones University, where she also served on the faculty of the radio/TV department.