Quick Answer
Perimenopause is the transition period (years before menopause) with irregular periods and symptoms. Menopause is one point in time - 12 months after your last period. Postmenopause is all years after menopause.
The Three Stages
Perimenopause (The Transition)
- • Timing: Usually begins in 40s (can start in 30s)
- • Duration: Average 4 years, but can be 1-10 years
- • What happens: Ovaries gradually produce less estrogen
- • Periods: Become irregular - longer, shorter, heavier, lighter, skipped
- • Can you get pregnant?: Yes! Still ovulating sporadically
Menopause (The Milestone)
- • Definition: 12 consecutive months without a period
- • Average age: 51 years in the US
- • Pregnancy: No longer possible naturally
Postmenopause (After Menopause)
- • When: All years after menopause
- • Symptoms: Hot flashes may continue but usually lessen over time
- • Health concerns: Increased risk for osteoporosis, heart disease
Perimenopause Symptoms
Hot Flashes & Night Sweats
Sudden intense heat, flushing, and sweating. Night sweats are hot flashes that happen during sleep, often disrupting rest.
Sleep & Mood
- • Insomnia: Difficulty falling or staying asleep
- • Mood swings: Irritability, emotional ups and downs
- • Brain fog: Memory lapses, difficulty concentrating
Medical Review
Reviewed by: Ricardo Hamilton, MD
Last Updated: January 7, 2026
Sources: North American Menopause Society (NAMS), Mayo Clinic