The three stagesPerimenopause, menopause, and the years after
Perimenopause is the transition, and it is where most of the confusion lives. Cycles shorten, then lengthen, then skip. Bleeding can become heavier before it stops altogether. Hot flushes, disturbed sleep, irritability and difficulty concentrating begin while periods are still happening, which is precisely why they are so often attributed to stress, thyroid disease or "hormonal imbalance" instead. In India this phase commonly begins in the late thirties or early forties.
Menopause itself is a single point in time, identified backwards: twelve consecutive months with no period. In a woman over 45 with typical symptoms, that history is the diagnosis. Guidelines are explicit that hormone tests should not be used to identify perimenopause or menopause at this age, because FSH fluctuates from week to week and the result does not change management. Below 45 the tests become useful again, and below 40 they are essential, because that is a different diagnosis.
Postmenopause is everything afterwards. Hot flushes usually fade over a few years. Vaginal and urinary symptoms usually do not — they tend to progress — and the consequences of low oestrogen for bone accumulate quietly. Indian women reach menopause around four to five years earlier than the widely quoted global average of 51, which means more years spent in this phase, not fewer.
Two situations are not simply "early versions" of the same thing. Menopause between 40 and 45 is early menopause; periods stopping before 40 is premature ovarian insufficiency. Both are assessed differently, and in both, hormone treatment is usually continued at least to the average age of menopause for reasons of bone and cardiovascular health rather than symptom relief alone. Surgical menopause, after removal of both ovaries, is abrupt rather than gradual and the symptoms are correspondingly more severe.