What Is Perimenopause? Signs, Stages and What to Expect

Perimenopause is the transition leading up to menopause, when the ovaries’ hormone production becomes irregular and then declines. It usually begins in the mid-to-late 40s and lasts about four years on average, though it can be shorter or longer. It ends once you have gone 12 months without a period. A change in your periods is often the first sign.

What is perimenopause?

Perimenopause means "around menopause." It is the phase when the ovaries gradually wind down. Ovulation becomes less predictable, hormone levels rise and fall irregularly, and periods change until they eventually stop.

Menopause itself is a single point in time. The World Health Organization defines natural menopause as 12 consecutive months without a period, with no other physical cause and no medical intervention responsible. Everything after that point is called postmenopause.

A note on terms: researchers often use "menopausal transition" for the time from the first cycle changes to the final period, and some definitions of perimenopause also include the 12 months after the final period. In everyday use, including by the NHS, perimenopause usually means the years when you have menopause-related symptoms but your periods have not yet stopped. That is how we use it on Midlife Atlas.

When does perimenopause start?

Perimenopause usually starts in the mid-to-late 40s, according to the US Office on Women’s Health. The WHO notes that natural menopause generally happens between 45 and 55 in women worldwide, and in the United States the average age of the final period is 51.

Timing varies from person to person. Some factors linked with an earlier transition include:

• Smoking. People who smoke tend to reach menopause earlier than non-smokers.
• Ethnicity. US research suggests Black and Hispanic women may reach menopause roughly two years earlier than White or Asian women, according to the British Menopause Society’s patient charity, Women’s Health Concern.
• Medical treatment. Surgery to remove the ovaries, chemotherapy and pelvic radiotherapy can bring on menopause suddenly.
• Family history may also play a part, although it cannot predict your own timing precisely.

Menopause between ages 40 and 44 is called early menopause. Menopause before 40 is called premature ovarian insufficiency (POI). See our guide to early menopause. If you have menopause-type symptoms before 45, it is worth speaking to a doctor, because the assessment and long-term health advice differ for younger people. For more on timing and risk factors, see when perimenopause starts.

If you have had a hysterectomy but still have your ovaries, you can still go through perimenopause. You will not have periods to track, so clinicians rely on the pattern of your symptoms instead.

What are the stages of perimenopause?

The most widely used research framework for the menopause transition is STRAW+10, published in 2012. It divides perimenopause into two main stages based on your bleeding pattern.

After the late transition comes the final menstrual period, which can only be identified in hindsight, once 12 months have passed.

STRAW+10 is a research and clinical framework, not a home test. Not everyone follows the pattern neatly. Research summarized by the US Centers for Disease Control and Prevention found that between 12% and 25% of women have little or no change in cycle length before their final period.

How long does perimenopause last?

On average, perimenopause lasts about four years before periods stop, according to the US Office on Women’s Health. For some people it lasts a few months; for others it continues for up to about a decade.

Symptoms can outlast perimenopause itself. The Study of Women’s Health Across the Nation (SWAN), a large multi-ethnic US study, followed women with frequent hot flashes or night sweats:

• The median total duration of these symptoms was 7.4 years.
• Symptoms continued for a median of 4.5 years after the final period.
• African American women had the longest duration, with a median of 10.1 years.
• Women whose symptoms began earlier in the transition tended to have them for longer.

The NHS similarly notes that women from a Black ethnic background are more likely to have hot flashes that are severe and last longer.

These are averages across large groups. No test can tell you how long your own perimenopause or symptoms will last. Our guide to how long perimenopause lasts covers the stage-by-stage timeline.

What happens to your hormones during perimenopause?

During perimenopause, your ovaries respond less consistently to the signals from your brain. Three changes explain most of what people notice:

• Estrogen fluctuates. Levels can swing higher or lower than usual from month to month before falling more steadily in late perimenopause. (Estrogen is spelled "oestrogen" in the UK.)
• Ovulation becomes irregular. Progesterone is mainly produced after ovulation, so cycles without ovulation mean less progesterone. Without regular progesterone, the womb lining can build up more than usual, which is one reason periods can become heavier.
• Follicle-stimulating hormone (FSH) rises. As the ovaries respond less, the brain produces more FSH to stimulate them. FSH levels still rise and fall considerably during perimenopause.

Because these hormones change so much from week to week, a single blood test gives only a snapshot. This is why guidelines rarely recommend hormone tests to identify perimenopause in people over 45. See hormone changes during perimenopause for a fuller explanation.

What are the common signs and symptoms?

Symptoms vary widely. A fact sheet produced with the NHS National Menopause Clinical Reference Group estimates that around 75% of women have symptoms and about 25% have severe ones. Up to 80% experience hot flashes or night sweats at some point during the transition.

Common symptoms include:

• Period changes: irregular periods, shorter or longer cycles, skipped periods and heavy bleeding
• Heat and sweating: hot flashes (called hot flushes in the UK) and night sweats
• Sleep and energy: sleep problems and fatigue
• Mood and thinking: anxiety, low mood, irritability and brain fog
• Body: joint pain, headaches, heart palpitations and weight changes
• Vaginal, urinary and sexual health: vaginal dryness, urinary changes and low libido

You may have many of these, a few, or hardly any. See the early signs of perimenopause for what tends to appear first. Symptoms can also come and go, which makes a written record useful. Our private Symptom Explorer lets you log symptoms and prepare a summary without storing anything on our servers.

Could it be something else?

Many perimenopause symptoms overlap with other common conditions. It is worth keeping an open mind, particularly if your symptoms are unusual, severe or started suddenly. Conditions that can look similar include:

• Thyroid problems, which can affect energy, heart rate, temperature, weight and periods
• Iron-deficiency anemia, which heavy periods can cause, leading to tiredness, breathlessness and dizziness
• Depression or anxiety disorders, which may need their own assessment and treatment
• Sleep disorders, such as sleep apnea
• Fibroids or polyps in the womb, which can cause heavier or irregular bleeding
• Medication side effects and pregnancy

A clinician can help work out whether perimenopause explains the full picture or whether another cause needs checking. Our guide to perimenopause or something else goes into more detail.

How is perimenopause diagnosed?

For most people over 45, perimenopause is identified from symptoms, not tests. Guidance in the UK and US points the same way.

If you are 45 or older: the UK’s National Institute for Health and Care Excellence (NICE) advises that perimenopause can be identified without laboratory tests in otherwise healthy people who have recently started having hot flashes or night sweats along with changes in their menstrual cycle. NICE specifically advises against using tests such as anti-Müllerian hormone (AMH), inhibin, estradiol, antral follicle count or ovarian volume for this purpose in this age group.

If you are between 40 and 45: NICE suggests a clinician may consider an FSH blood test to help confirm menopause when there are symptoms, including cycle changes.

If you are under 40: blood tests are used to investigate possible premature ovarian insufficiency.

In the US, the Office on Women’s Health similarly notes that hormone tests are not usually recommended unless periods stop at a young age, because hormone levels rise and fall unpredictably during the transition.

A few other points are worth knowing:

• Hormonal contraception can hide the picture. Some methods cause regular bleeds, while others make periods lighter or stop them, which makes it harder to tell whether you are in perimenopause. FSH results are also unreliable while using combined hormonal contraception.
• Other tests may still be useful. Depending on your symptoms, a clinician may suggest tests to rule out other causes, such as a thyroid problem or anemia.
• Home FSH tests have limits. Because FSH swings during perimenopause, one result cannot confirm or rule it out. See perimenopause tests.

Can you get pregnant during perimenopause?

Yes. Fertility falls during perimenopause, but ovulation can still happen, sometimes after months without a period. If you do not want to become pregnant, you still need contraception.

UK guidance from the Faculty of Sexual and Reproductive Healthcare (FSRH) and the NHS advises that, if you are not using hormonal contraception, you can stop:

• 2 years after your last period if it happened before age 50
• 1 year after your last period if it happened at 50 or older
• At age 55, contraception is no longer needed for anyone

Guidance in other countries may differ, so check with your clinician what applies to you. Our guide to pregnancy during perimenopause compares contraceptive methods.

Two points often cause confusion:

• Hormone therapy (HRT) does not work as contraception. It uses similar hormones, but not at doses that reliably prevent pregnancy. A progestogen-only method, such as the progestogen-only pill, implant or hormonal IUD, or a non-hormonal method can be used alongside it.
• Combined contraception can double as symptom relief. For people under 50 who can safely use it, the combined pill, patch or ring can ease perimenopausal symptoms and may be used instead of HRT. The NHS does not recommend the combined pill from age 50, because the risks generally outweigh the benefits.

What treatments and support are available?

The right approach depends on your symptoms, your health history, your age and what matters most to you. The options below are an overview, not a recommendation for any individual. Please do not start or stop a prescription medicine based on a general article.

Everyday measures. Keeping active, protecting your sleep, cutting back on alcohol and stopping smoking all support your broader health. Smoking is also linked with worse hot flashes. Practical steps such as layered clothing and a cooler bedroom can make hot flashes and night sweats easier to manage.

Menopause-specific CBT. In its November 2024 update, NICE recommended that menopause-specific CBT be considered for hot flashes, night sweats, sleep problems and low mood linked to menopause. It can be used alongside HRT or instead of it. The evidence shows the biggest effect is on how distressing or disruptive symptoms feel.

Hormone therapy. Hormone therapy is called HRT in the UK, menopausal hormone therapy (MHT) in Australia and hormone therapy (HT) in the US. The Menopause Society describes it as the most effective treatment for hot flashes and night sweats. Its 2022 position statement concludes that, for people under 60 or within 10 years of menopause who have no contraindications, the benefits generally outweigh the risks for treating bothersome hot flashes and preventing bone loss.

Risks depend on the type, dose, route and timing. For example, patches and gels may carry a lower risk of blood clots and stroke than tablets. During perimenopause, while periods are still happening, a cyclical (sequential) regimen is commonly used.

Non-hormonal prescription medicines. NICE now recommends fezolinetant as an option for moderate to severe hot flashes and night sweats when HRT is unsuitable. Some antidepressants, gabapentin and clonidine are also used, although NICE advises against offering them routinely as first-line treatment for hot flashes alone. Which medicines are available differs by country.

Treatments for heavy or irregular bleeding. Options include tranexamic acid, which is taken only on bleeding days, and the hormonal IUD. The hormonal IUD reduces heavy and irregular bleeding, provides contraception, and can form the progestogen part of HRT.

Vaginal estrogen. For vaginal dryness, discomfort or urinary symptoms, NICE recommends offering low-dose vaginal estrogen, including to people already using HRT.

Supplements. NICE notes some evidence that isoflavones or black cohosh may ease hot flashes. However, preparations vary widely and their safety is uncertain. Supplements can interact with other medicines, so tell your clinician what you take.

How does perimenopause affect long-term health?

As estrogen levels fall, bone density declines and cardiovascular risk rises. People who reach menopause early face a higher risk of bone loss and heart disease. The WHO describes menopause as a useful moment to reassess your health.

Perimenopause is a sensible time to:

• Check your blood pressure and ask about cholesterol and diabetes screening
• Review your risk factors for osteoporosis, such as family history, low body weight, smoking or long-term steroid use
• Keep up with breast and cervical screening where you live
• Build strength and weight-bearing exercise into your week

Common misconceptions about perimenopause

"You need a blood test to know." Most people over 45 do not. Perimenopause is usually identified from symptoms and cycle changes.

"It starts at 50." Perimenopause usually starts in the 40s. For most people, menopause itself happens between 45 and 55.

"If your periods are still regular, it can’t be perimenopause." Period changes are usually the first sign, but not always. Some people notice other symptoms first, and a minority see little change in cycle length before their final period.

"Hot flashes only last a year or two." For people with frequent hot flashes, SWAN found a median duration of 7.4 years.

"You can’t get pregnant anymore." You can, until the point set out in contraception guidance.

"HRT works as contraception." It does not.

When should you see a doctor?

Book a routine appointment if:

• Symptoms are affecting your sleep, work, relationships or wellbeing
• You are under 45 and think you have menopause symptoms
• You would like to talk about treatment or contraception
• Changes to your periods are worrying you

Get checked promptly if you have:

• Bleeding after sex or between periods
• Very heavy bleeding. Signs include soaking through one or more pads or tampons every hour for several hours, needing to double up on protection, bleeding for more than 7 days, or passing clots about the size of a quarter (2.5 cm) or larger
• Any vaginal bleeding 12 months or more after your last period
• Periods that stop before age 40
• Heavy periods together with breathlessness, dizziness or unusual tiredness, which can signal anemia

Seek emergency care if very heavy bleeding comes with chest pain, shortness of breath or feeling faint. If low mood includes thoughts of harming yourself, contact emergency services or a crisis line in your country straight away.

What should you ask at your appointment?

Our full guide to preparing for a perimenopause appointment includes a checklist. In short, it helps to bring notes covering two or three months of period dates, your main symptoms and when they happen, any medicines or supplements you take, and your family history of breast cancer, blood clots, heart disease and osteoporosis.

Questions you might ask:

1. Do my symptoms fit with perimenopause, or should anything else be checked?
2. Do I need any tests, and what would the results change?
3. Which treatment options suit my health history, and what are the benefits and risks of each?
4. What are my options if I would prefer not to use hormones?
5. Do I still need contraception, and which methods work alongside treatment?
6. What should I do about heavy or irregular bleeding?
7. Is there anything I should do now for my bone and heart health?
8. When should we review how things are going?

What happens next?

Perimenopause does not follow a fixed script. For what comes next, see our complete guide to menopause. Many people find that gaps between periods lengthen as they move into the late transition, and some symptoms ease while others appear. Once you reach 12 months without a period, you have reached menopause.

Some symptoms can continue after periods stop. Vaginal dryness and urinary symptoms may appear or worsen later. Whatever you decide about treatment now can be revisited as your needs change.

Frequently asked questions

What age does perimenopause usually start?

Most people notice perimenopause in their mid-to-late 40s. It can start earlier, and symptoms before 45 are worth discussing with a doctor.

What are the first signs of perimenopause?

A change in your periods is usually the first sign. They may come more or less often, or become heavier or lighter. Some people first notice sleep problems, mood changes or hot flashes.

Can a blood test confirm perimenopause?

Not reliably, because hormone levels swing during perimenopause. For people over 45, clinicians usually rely on symptoms and cycle changes. Blood tests are more useful for people under 45, or to rule out other conditions.

Can perimenopause start in your 30s?

It is less common, but some people notice changes earlier. Menopause before 40 is called premature ovarian insufficiency and needs medical assessment, so see a doctor if you have symptoms at this age.

How do I know when perimenopause is over?

Perimenopause ends when you have had no period for 12 months in a row. If you use hormonal contraception or HRT that affects bleeding, this can be hard to tell, so ask your clinician how to judge it in your situation.

References

1. World Health Organization: Menopause fact sheet
2. NICE guideline NG23: Menopause, identification and management (recommendations)
3. NICE: Updated menopause guidance and HRT discussion aid (November 2024)
4. NHS: Symptoms of menopause and perimenopause
5. NHS inform: Signs and symptoms of menopause
6. US Office on Women’s Health: Menopause basics
7. ACOG: Perimenopausal bleeding and bleeding after menopause
8. ACOG: Heavy menstrual bleeding
9. ACOG: Abnormal uterine bleeding
10. Harlow SD et al. Executive summary of STRAW+10 (2012), via ASRM
11. CDC Stacks: Menstrual cycle changes as women approach the final menses
12. Avis NE et al. Duration of menopausal vasomotor symptoms over the menopause transition. JAMA Internal Medicine, 2015
13. The 2022 hormone therapy position statement of The North American Menopause Society. Menopause, 2022
14. FSRH Contraception Choices: Perimenopause and menopause
15. FSRH guideline: Contraception for women aged over 40 years
16. Women’s Health Concern (British Menopause Society): Perimenopause and menopause fact sheet, April 2026
17. Self-Care Forum and NHS National Menopause Clinical Reference Group: Fact sheet no. 17, Menopause
18. Australasian Menopause Society: Bleeding in perimenopause, postmenopause and on MHT

Editorial status: evidence-based educational article. Last evidence check: September 10, 2026.