What changes first in perimenopause?

Perimenopause is the transition leading up to menopause, and it commonly begins with changes to the menstrual cycle rather than with the symptoms people most associate with menopause. Cycles becoming shorter, longer, heavier or less predictable is often the first thing noticed.

Hot flushes, night sweats, disturbed sleep and mood changes may follow, but the order and the intensity vary widely, and some people notice very little. The National Institute on Aging describes this transition as lasting years rather than months, which is part of why it is often recognised only in hindsight.

Menopause itself is defined retrospectively, as twelve consecutive months without a period. Bleeding after that point is a separate matter and is a reason to see a clinician promptly rather than attribute it to the transition.