Perimenopause is the time leading up to menopause. Your ovaries make hormones unevenly, and your periods start to change. It usually begins in your 40s and lasts about four years on average. Common signs are irregular periods, hot flashes and poor sleep, though some women notice very little. Pregnancy is still possible during perimenopause.
Wondering if this is you? Our free perimenopause quiz takes about 5 minutes.
In short
- Perimenopause is the time leading up to menopause. Your ovaries make hormones unevenly and release an egg less often, so your periods start to change.
- Irregular periods are generally the first sign of perimenopause, according to Cleveland Clinic. Hot flashes, night sweats and trouble sleeping are other common signs. Some women have no symptoms or only a few mild ones, says the American College of Obstetricians and Gynecologists (ACOG).
- Perimenopause usually starts in your 40s and lasts about four years on average. It can last a few months or up to 8 years, according to Cleveland Clinic. See when perimenopause starts and how long it lasts.
- Pregnancy is still possible in perimenopause, even if you skip periods, says the Office on Women's Health (OWH).
- Doctors can usually recognize perimenopause from your age, your symptoms and changes in your periods, according to the OWH. Blood hormone tests are not usually needed. If your periods stop before age 40, you can ask about testing.
Perimenopause definition, source by source
Sources word it differently. They agree on the core: perimenopause is the lead-up to menopause, and your hormones and periods are changing.
| Source | How it describes perimenopause |
|---|---|
| ACOG | The years leading up to menopause. Estrogen from your ovaries starts to go up and down in your 30s and 40s |
| National Institute on Aging (NIA) | The time leading up to menopause, also called the menopausal transition |
| OWH | The time before menopause when your hormone levels change |
| Cleveland Clinic | When your body starts transitioning to menopause and your ovaries begin making less of their hormones |
| STRAW+10 | The staging system doctors and researchers use. The word means the time around menopause. Perimenopause starts when back-to-back cycles differ in length by 7 days or more, and this happens again within 10 cycles. It ends 12 months after your last period |
Perimenopause is not menopause. You reach menopause after 12 months in a row with no period or spotting, says the OWH. Our guide to perimenopause, premenopause and menopause explains the three words. It also has a short stage check.
What happens in your body
Estrogen and progesterone are two of the hormones your ovaries make, says the NIA. Estrogen helps control your menstrual cycle (ACOG).
In perimenopause, the ovaries make hormones unevenly and release an egg less often, according to The Menopause Society. That is what changes your periods. Cleveland Clinic notes it's common for hormone levels to go up and down, like a rollercoaster. During the transition, production of estrogen and progesterone declines greatly. These changes may explain the symptoms some women have (NIA).
How perimenopause usually shows up
Symptoms vary a lot. ACOG notes that some women have only a few mild ones, while others have many that can be severe. Common signs include:
- Period changes. Cycles can get shorter or longer, you may skip periods, and flow can get lighter or heavier (ACOG). See our guide to how periods change in perimenopause.
- Hot flashes and night sweats. A hot flash is a sudden feeling of heat, most often in the upper body and face. Night sweats are hot flashes at night (NIA).
- Trouble sleeping and mood changes. You may not fall asleep easily or may wake too early, and you might feel moodier or more irritable (NIA).
- Vaginal dryness. The lining of the vagina may become thinner, drier and less elastic, and dryness may cause pain during sex (ACOG).
Some of these signs look like signs of other conditions. Cleveland Clinic advises talking to your provider. Our perimenopause symptoms list groups the common signs and has a checklist for your doctor visit.
When perimenopause starts and how long it lasts
Most sources say perimenopause starts in your 40s, sometimes as early as the mid-30s. It lasts about four years on average. For some women it is a few months, and for others up to 8 years (Cleveland Clinic) or 10 years (OWH).
How doctors recognize it
Your provider can usually tell whether you are in perimenopause from your age, your symptoms and changes in your periods, says the OWH. Blood hormone tests are not usually needed. Cleveland Clinic explains that hormone levels change so much that the tests aren't reliable. The NIA notes that a doctor may suggest a blood test in some cases, for example if your periods stopped at an early age.
An ACOG expert article says doctors first rule out other causes of abnormal bleeding. These include thyroid problems, growths in the uterus (polyps or fibroids) and infection. A doctor may use a pelvic exam, blood tests or an ultrasound. If nothing else is found, perimenopause is the likely explanation for irregular periods, especially in your 40s.
Can you still get pregnant in perimenopause?
Yes. You can get pregnant during perimenopause, even if you skip periods (OWH). Cleveland Clinic adds that as long as you have a period, you can still get pregnant, though you may be less likely to. If you don't want to get pregnant, the NIA advises using birth control for at least 12 months after your last period. Ask your doctor when it's safe to stop.
Want to see how your symptoms add up? Our free 5-minute quiz uses your age, your cycle and 21 common symptoms, scored on the Greene Climacteric Scale. It gives you an estimate of your phase, not a diagnosis. You see your result before we ask for your email, and you can skip that step. A detailed personal report is available for a one-time fee of $39 if you want one. Take the free perimenopause quiz
When to see a doctor
Changes in your periods are normal in perimenopause, but ACOG says to report them. Abnormal bleeding may be a sign of a problem. The NIA advises seeing your doctor if:
- your periods come very close together
- you have heavy bleeding
- you bleed or spot after sex or between periods
- your periods last more than a week
- you bleed or spot again after more than a year without a period
Cleveland Clinic adds large blood clots, a need to change a pad or tampon every 1 to 2 hours, and periods less than 21 days apart. The OWH advises seeing your provider right away for bleeding after 12 months with no period.
Cleveland Clinic suggests contacting a provider if your symptoms are unbearable or interfere with your quality of life. For mood changes, the NIA advises talking with a primary care provider or a mental health professional. If you are thinking about harming yourself, call or text 988 to reach the 988 Suicide & Crisis Lifeline (OWH).
Frequently asked questions
Is perimenopause real? Yes. ACOG, the NIA and Cleveland Clinic all describe it, and the STRAW+10 staging system marks when it starts and ends. Cleveland Clinic calls it a natural and normal progression that comes with physical and emotional symptoms.
How do I know if I'm in perimenopause? The OWH says your provider can usually tell from your age, your symptoms and changes in your periods. It advises tracking your periods and symptoms and sharing them with your provider. Our quiz gives an estimate, not a diagnosis.
Can perimenopause be stopped or treated? Cleveland Clinic says there isn't any treatment to stop perimenopause, and calls it a natural part of life. A provider may recommend ways to ease symptoms. Many people don't need medication, while others find it relieves their symptoms, the clinic adds. The NIA notes that many women have mild symptoms that can be managed with lifestyle changes, such as avoiding caffeine, dressing in layers or carrying a portable fan. For women who want treatment, options may include lifestyle changes, nonhormonal medicines and hormones. Ask your doctor what fits your symptoms and health history.
Sources
- American College of Obstetricians and Gynecologists. The Menopause Years. Accessed October 2026.
- American College of Obstetricians and Gynecologists. My Periods Have Changed. Is Menopause Around the Corner? Accessed October 2026.
- National Institute on Aging. What Is Menopause? Accessed October 2026.
- Office on Women's Health. Menopause basics. Accessed October 2026.
- Office on Women's Health. Menopause symptoms and relief. Accessed October 2026.
- MedlinePlus, National Library of Medicine. Menopause. Accessed October 2026.
- The Menopause Society. Perimenopause. Accessed October 2026.
- Cleveland Clinic. Perimenopause. Accessed October 2026.
- Harlow SD, et al. Executive summary of the Stages of Reproductive Aging Workshop + 10 (STRAW+10). 2012.
This article is for education. It isn't medical advice and doesn't replace a visit with your doctor. Decodemeno sells a personal perimenopause report. Sources checked October 29, 2026.