How Perimenopause and Menopause Are Diagnosed

A lot of women expect a blood test to settle the question. There isn’t one, at least not a single test that works on its own, and knowing that up front saves a frustrating conversation with a doctor who orders a “normal” FSH and sends you home still symptomatic.

How Perimenopause Is Diagnosed

For women 45 and older, UK guidance from NICE is explicit: base the diagnosis on symptoms and menstrual history, not a blood test.[1] Irregular cycles, hot flashes, sleep and mood changes, at the right age, are enough to diagnose perimenopause and start treatment if you want it.

The reason a blood test is skipped isn’t that it wouldn’t be useful in theory. It’s that FSH swings up and down throughout perimenopause rather than settling into a clear high or low pattern, so a single measurement can look completely normal in a woman who is deep in the transition. A normal result doesn’t rule anything out.

Testing does have a place before 45. Under 40, it’s used to investigate premature ovarian insufficiency, a distinct diagnosis. Between 40 and 45, or in women who’ve had a hysterectomy and can’t track cycle changes, blood work adds useful information the symptom picture alone can’t provide.

Diagnosis on Hormonal Contraception

The combined pill, patch, and ring make this harder still. These methods work by suppressing your own cycle and replacing it with a steady synthetic dose. That masks the two things a doctor would normally look for: your natural cycle pattern and your FSH level. Synthetic estrogen suppresses pituitary FSH output, so a blood test taken while you are still using combined hormonal contraception can read normal or low even if your ovaries are well into the transition underneath it.

UK guidance generally treats age 50 as the point where combined hormonal contraception is reviewed, with a switch to a non-estrogen method commonly recommended around then regardless of whether menopause has been formally confirmed.[4] In practice, this means many women simply switch methods around 50 without ever getting a formal diagnosis while still on combined contraception, and that is an accepted, normal outcome rather than a diagnostic failure.

Bleeding pattern is not a useful clue on the combined pill, since the method controls it directly. New hot flashes, sleep changes, or mood symptoms that show up despite the steady synthetic hormone level are a more useful signal than any blood test taken while you’re on the method.

How Menopause Is Diagnosed

Menopause has an unusually clean definition: twelve consecutive months with no period, with no other explanation for the gap.[2] That definition is retrospective by nature. You cannot be told you’ve reached menopause while it’s happening. You can only look back after a year has passed and confirm it.

This creates a real gap for two groups of women. Those who’ve had a hysterectomy but kept their ovaries have no periods to count, so the twelve-month rule doesn’t apply. Women on hormonal contraception that suppresses or masks natural cycles face the same problem. In both cases, a doctor leans more on symptoms, age, and sometimes hormone testing, since the usual marker isn’t available.

How Do I Know What Stage I’m In?

Researchers use a staging system called STRAW+10 to map the whole transition, from the first subtle hormone shifts through to years after the final period.[2] The full breakdown is here, but the short version: cycles that shift by a week or so mark early perimenopause; a gap of 60 days or more between periods marks the late stage, which usually runs one to three years before the final period.

There’s no single test that places you precisely on this map. It’s read from your cycle pattern and symptoms over time, which is a strong argument for tracking both rather than trying to recall them from memory at an appointment.

Do At-Home Test Kits Work?

Over-the-counter kits that measure FSH from a urine sample are widely sold. The FDA classifies them as accurately detecting elevated FSH most of the time, but is clear that detecting elevated FSH is not the same as confirming perimenopause or menopause.[3] These kits carry the exact same limitation as a single blood test: a snapshot of one moment in a hormone pattern that swings, especially during perimenopause. A negative result doesn’t mean you’re not in the transition, and a positive one doesn’t confirm you are.

Frequently Asked Questions

Is there a test for perimenopause?

Not a single reliable one. Diagnosis in women 45 and older is based on symptoms and cycle changes. Blood tests have a role for women under 45, but even then, results need to be read alongside the clinical picture, not on their own.

How does a doctor know if you’re in perimenopause?

Mainly from your age, your symptoms, and how your cycle has changed. If you’re over 45 with irregular periods and typical symptoms, that combination is usually enough for a doctor to diagnose perimenopause without ordering blood work.

How can I tell if I’ve reached menopause?

Officially, only in hindsight: twelve months in a row without a period confirms it. If you’ve had a hysterectomy or your cycles are suppressed by contraception, that marker isn’t available, and a doctor will look at age, symptoms, and sometimes hormone levels instead.

---

References

[1] National Institute for Health and Care Excellence. (2015, updated 2019). Menopause: Diagnosis and management (NICE guideline NG23). NICE. https://www.nice.org.uk/guidance/ng23

[2] Harlow, S. D., Gass, M., Hall, J. E., et al. (2012). Executive summary of the Stages of Reproductive Aging Workshop +10: addressing the unfinished agenda of staging reproductive aging. Menopause, 19(4), 387-395. https://pmc.ncbi.nlm.nih.gov/articles/PMC3340903/

[3] U.S. Food and Drug Administration. Home Use Tests: Menopause. https://www.fda.gov/medical-devices/home-use-tests/menopause

[4] Faculty of Sexual and Reproductive Healthcare. (2010, amended 2017). Contraception for Women Aged Over 40 Years. FSRH. https://www.fsrh.org/standards-and-guidance/documents/fsrh-guidance-contraception-for-women-aged-over-40-years-2017/