High FSH: What It Means and What to Do Next
High FSH (follicle-stimulating hormone) means your pituitary gland is working harder to stimulate ovaries or testes that are responding less. In women, the most common reason is the menopause transition: Quest's early-cycle range is 2.5–10.2 mIU/mL and its postmenopausal range is 23.0–116.3 mIU/mL. What counts as high depends on your cycle day, age and sex, and during perimenopause FSH can be high one month and normal the next, so a single result rarely settles anything. Under 40, FSH that stays above 25 mIU/mL on 2 tests at least 4 weeks apart, with missed periods, points to primary ovarian insufficiency and should be seen by a doctor. In men (about 1.5–12.4 mIU/mL), high FSH usually means the testes are not making sperm normally.
What Causes High FSH?
Perimenopause
As the ovaries run low on eggs they make less estradiol and inhibin, and the pituitary raises FSH to compensate. In the years before the last period, FSH rises and falls from cycle to cycle.
Menopause
After menopause FSH stays high for good, typically in Quest's postmenopausal range of 23.0–116.3 mIU/mL, with low estradiol. Over 45 with typical symptoms, menopause is usually diagnosed without a blood test.
Primary Ovarian Insufficiency
The ovaries stop working normally before age 40. It can be autoimmune, genetic (Turner syndrome, a fragile X premutation) or have no clear cause. Periods and even ovulation can still come back now and then, unlike menopause.
Lower Ovarian Reserve
In women trying to conceive, an FSH above about 10 mIU/mL on cycle day 2–5 suggests fewer eggs remain. AMH is a steadier measure of reserve than FSH.
Testing at Mid-Cycle
FSH surges with LH just before ovulation, up to about 33.4 mIU/mL. A test drawn mid-cycle can look high when nothing is wrong, which is why baseline testing is done on cycle day 2–5.
Chemotherapy, Radiation or Surgery
Cancer treatment and surgery on the ovaries or testes can damage the cells that make eggs, sperm and sex hormones, raising FSH.
Testicular Failure in Men
Klinefelter syndrome, past mumps of the testes, injury, undescended testes and cancer treatment can all impair sperm production. The pituitary responds by raising FSH, often alongside low testosterone and high LH.
Associated Symptoms
What to Do Next
1. Retest to confirm
A single abnormal result should be confirmed with a repeat test. Temporary factors like stress, illness, or medications can affect results.
2. Related tests to consider
3. When to see a doctor
If your FSH is significantly abnormal, if you have severe symptoms, or if repeated results confirm the abnormality, consult a healthcare professional for appropriate evaluation and treatment.
Related Conditions
Frequently Asked Questions
Related Articles
This page is for informational purposes only and does not constitute medical advice. Consult a healthcare provider for interpretation of your results.
Content reviewed for accuracy by the JustLabs editorial team.