From Vogue:

It’s been 200 years since a French physician coined the term “menopause.” And for most of that time, it was spoken of in euphemisms (“she’s going through ‘the change’”). However, the conversation is finally shifting—now, you can’t open Instagram without hearing about it. Menopause itself is simply the day that marks 12 months since your last period, which usually happens between the ages of 45 and 55. But perimenopause starts up to 10 years earlier, during which fluctuating estrogen levels can cause a smorgasbord of unpleasant symptoms, from hot flushes and brain fog to aching joints and vaginal dryness. There are new treatments, too—like hormone replacement therapy.