Guide
When does perimenopause start?
Perimenopause, the transition to menopause, usually starts in the mid- to late 40s, though it can begin earlier. Most women begin it between 45 and 55, and it lasts about four years on average, sometimes two to eight. Menopause itself is reached after 12 months without a period; the average US age is about 51 to 52.
At what age does perimenopause usually start?
Perimenopause usually starts in a woman’s mid- to late 40s. The National Institute on Aging says most women begin the menopausal transition between ages 45 and 55, and MedlinePlus notes it can sometimes start earlier. Office on Women’s Health
Perimenopause is the transition to menopause: the years when hormone levels shift and periods change, before they stop for good. Office on Women’s Health
Menopause is the point when you have not had a period or spotting for a full year. National Institute on Aging
- Most women begin the menopausal transition between 45 and 55. National Institute on Aging
- The transition usually begins in the 40s, but sometimes it can start earlier. MedlinePlus
How long does perimenopause last?
For most women the transition lasts about four years, but it can run anywhere from two to eight years before periods stop permanently. The timing and symptoms vary widely from person to person. Office on Women’s Health
The National Institute on Aging also puts menopause-related symptoms at between two and eight years, while stressing how variable the timing is. National Institute on Aging
What is the average age of menopause?
About 51 to 52 in the US. The National Institute on Aging and the Office on Women’s Health give 52 as the average age; ACOG gives 51. The Office on Women’s Health puts the typical range between 45 and 58. National Institute on Aging
The Office on Women’s Health gives 52 as the US average, with a typical range of 45 to 58. Office on Women’s Health
| Source | Average age |
|---|---|
| National Institute on Aging | 52 |
| Office on Women’s Health | 52 (typical range 45 to 58) |
| ACOG | 51 |
What are the first signs of perimenopause?
Usually a change in periods. The National Institute on Aging says the transition usually starts with changes in menstrual patterns, often with hot flashes or other symptoms, and that period changes may be the first thing you notice. National Institute on Aging
- Periods that come closer together or further apart: The Menopause Society describes the time between periods varying by 7 days or more, and later skipped periods of 60 days or more. The Menopause Society
- Hot flashes, trouble sleeping, vaginal dryness and mood changes are other common symptoms. MedlinePlus
Can perimenopause start early?
Yes. Menopause between 40 and 45 is called early menopause, and menopause before 40 is called premature menopause. About 5% of women go through early menopause naturally; it can also follow surgery to remove the ovaries, chemotherapy or pelvic radiation. Office on Women’s Health
Primary ovarian insufficiency (POI) is the term clinicians use when the ovaries stop working normally before age 40. A woman with POI may still have periods, if irregular ones, and may still get pregnant. NICHD
- Smoking is associated with an earlier onset of menopause and more severe symptoms. National Institute on Aging
- Smoking can bring menopause up to two years earlier than in women who do not smoke. Office on Women’s Health
- Family history, autoimmune diseases, HIV, chromosomal conditions and hysterectomy are also linked with earlier menopause. Office on Women’s Health
- Compared with White women, Black women are more likely to have an early onset of menopause. National Institute on Aging
Do you need a blood test to know you are in perimenopause?
Usually not after 45. NICE advises clinicians to diagnose perimenopause and menopause without laboratory tests in otherwise healthy women aged 45 or over who have menopause-associated symptoms. NICE guideline NG23
For people aged 40 to 45 with symptoms, including a change in periods, NICE says an FSH blood test may be considered to help confirm menopause. NICE guideline NG23
ACOG notes that for many people over 45 with typical symptoms, clinicians can assess perimenopause from symptoms and menstrual history without routine hormone testing. ACOG
The National Institute on Aging says a clinician may suggest a hormone blood test in some cases, for example if periods stopped at an early age. National Institute on Aging
Can you get pregnant during perimenopause?
Yes. Even when periods are irregular, pregnancy is still possible during perimenopause. The Menopause Society advises anyone who does not want to become pregnant to use birth control until menopause is confirmed, one year after the final period. The Menopause Society
The Office on Women’s Health adds that pregnancy is possible even if you miss a period for a month or a few months. Office on Women’s Health
When should you see a clinician about period changes?
Some bleeding changes deserve a visit rather than waiting. The National Institute on Aging lists periods that come very close together, heavy bleeding, bleeding after sex or between periods, periods lasting more than a week, and any bleeding after a year without a period. National Institute on Aging
Vaginal bleeding after menopause is not normal, and the Office on Women’s Health advises seeing a healthcare provider as soon as possible if it happens. Office on Women’s Health
Symptoms such as fatigue, sleep problems and weight change can also come from thyroid conditions; the menopause and thyroid guide explains how they overlap.
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When perimenopause starts: questions, answered
Can perimenopause start at 35?
It is uncommon. Most women begin the transition between 45 and 55. Menopause before 40 is called premature menopause, and clinicians use the term primary ovarian insufficiency when the ovaries stop working normally before 40, so symptoms in your 30s are worth discussing with a clinician.
How do I know if I am in perimenopause?
Changes in your periods, such as a shift of 7 or more days in their timing or skipped periods, often with hot flashes or sleep problems, are the usual signs. After 45, clinicians generally make the assessment from symptoms and period history rather than blood tests.
What is the difference between perimenopause and menopause?
Perimenopause is the transition, often lasting about four years. Menopause is a single point in time, reached when you have gone 12 months without a period or spotting.
Does smoking make menopause start earlier?
Yes. Smoking is associated with earlier menopause, by up to about two years, and with more severe symptoms.
Sources
- National Institute on Aging: What is menopause? (Jan 2026)
- Office on Women’s Health: Menopause basics (updated Apr 2, 2026)
- Office on Women’s Health: Early or premature menopause
- NICHD: Primary ovarian insufficiency (POI), condition information
- NICE guideline NG23: Menopause, identification and management (updated Apr 2026)
- ACOG: Do I need hormone testing during perimenopause?
- ACOG: The menopause years (FAQ)
- MedlinePlus: Menopause
- The Menopause Society: Perimenopause
Last reviewed October 7, 2026. Every source above was checked on or before that date. Educational information only, not medical advice; it does not replace a conversation with a licensed clinician. DiscoverMedica does not employ clinicians.