Menopause
Also called the change, change of life
Reviewed August 2026 against NHS, NIH and WHO references.
In short
Menopause is the point when periods have stopped for twelve months in a row, marking the end of the reproductive years. In the US the average age is around 51. It is a single day, defined only in hindsight; the years of symptoms before it are perimenopause.
A single day, named in hindsight
Menopause is not a phase; it is one specific day. It is the day that marks twelve full months since your last period. Because you can only count those twelve months looking backward, menopause is always diagnosed after the fact. The average age in the US is around 51.
The long stretch of symptoms most people mean when they say 'menopause' is really perimenopause, the transition before that day. Everything after it is postmenopause.
Why periods stop
Over time the ovaries release fewer eggs and make much less estrogen and progesterone. Eventually there is not enough of these hormones to build and shed the womb lining, so periods stop for good. The drop in estrogen is also what drives symptoms like hot flashes and vaginal dryness.
What it means going forward
Menopause is a normal life stage, not an illness. But because estrogen also helps protect bone and the heart, the lower levels afterward raise some long-term health risks, which is why care after menopause focuses on protection as well as easing symptoms.
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Related terms
Sources
This definition is for general information only and is not medical advice. Menopause care depends on your individual health history. Please talk to a qualified clinician about what is right for you.