Perimenopause is the transition, and menopause is a single point in time: the day you reach 12 months without a period. Most of the symptoms women call "menopause" (hot flushes, irregular periods, poor sleep) actually start in perimenopause, often years before that point.
In short
- Perimenopause starts with the first changes and ends 12 months after your last period.
- Menopause is confirmed in hindsight, after 12 months in a row without a period. The average age is 51.
- Over 45, perimenopause is usually diagnosed from your symptoms and cycle, without blood tests.
What is perimenopause?
Perimenopause is the time when your ovaries slowly wind down. According to the European Menopause and Andropause Society (EMAS), it begins with the first signs of approaching menopause and ends 12 months after your last period. Hormone levels go up and down rather than falling in a straight line, which is why symptoms can come and go.
Typical signs are periods that change (shorter or longer cycles, heavier or lighter bleeding, skipped months), hot flushes, night sweats, poor sleep, mood changes and brain fog. Read more in Things nobody tells you about perimenopause.
What is menopause?
Menopause is your final period. You can only know it in hindsight: the WHO defines natural menopause as 12 consecutive months without a period, with no other obvious cause. Everything after that is called postmenopause.
For most women this happens between 45 and 55. EMAS gives an average age of 51. Menopause before 40 is called premature menopause, and between 40 and 45 early menopause.
How long does perimenopause last?
It varies a lot. Cleveland Clinic gives an average of about four years, with a range from a few months to eight years or more. It usually starts in your mid-40s, but it can begin earlier. If you're wondering whether 40 is too young, see Perimenopause at 40: am I too young?
Can you get pregnant in perimenopause?
Yes. Your fertility is lower, but you still ovulate some months. As long as you have periods, pregnancy is possible, so keep using contraception until a doctor tells you it's safe to stop.
How do doctors tell the difference?
Usually from your age, your symptoms and your cycle. EMAS and NICE both say that in otherwise healthy women over 45, perimenopause and menopause can be diagnosed without lab tests. Hormone levels change from day to day in perimenopause, so a single blood test often says little. Germany's IQWiG notes that checking hormone levels has little practical value for confirming menopause.
Blood tests (FSH) are more useful under 45, when early or premature menopause needs to be confirmed or other causes ruled out.
When to see a doctor
Talk to your doctor if symptoms affect your sleep, work or relationships, or if your periods change before 45. See a doctor promptly if you have very heavy bleeding or bleeding between periods or after sex.
Always get checked if you have any bleeding after 12 months without a period, even if it's light or happens once.
Before the appointment, note your cycle and symptoms for a few weeks. Our guide How to talk to your doctor about perimenopause has a checklist.
Frequently asked questions
Is perimenopause the same as premenopause?
People often use the words the same way. Strictly, premenopause can mean all the years before menopause, while perimenopause means the transition with its changes.
Do symptoms stop at menopause?
Not always. Hot flushes often continue for some years after the last period. EMAS says most women have them for less than five years, but some for longer.
Can I be in perimenopause with regular periods?
Yes. Symptoms like night sweats, poor sleep or anxiety can start while your cycle still looks regular.
Do I need a blood test to know?
Usually not if you're over 45. Your doctor may suggest one if you're younger or if something else could explain your symptoms.
Not sure which stage you're in?
Pausie lets you log your periods and symptoms side by side, so you can see how your cycle changes over months. No account, and your diary stays on your phone.
This article is general information, not medical advice. Written by the Pausie team. Published and last reviewed 2 November 2026.
Sources
- EMAS Menopause Essentials: Technical definitions of menopause terms
- EMAS Menopause Essentials: Diagnostic tests for menopause
- EMAS Menopause Essentials: Menopausal symptoms
- WHO: Menopause fact sheet
- InformedHealth.org (IQWiG): Menopause
- NICE QS143: Diagnosing perimenopause and menopause
- Cleveland Clinic: Perimenopause