Perimenopause and symptoms that may surprise you

perimenopause starts earlier than you think

A study of over 1 million women, published in Nature Medicine in October 2026, found that hormone changes can start up to 15 years before your final period. With the average final period around 50, that puts the start in the late 30s for many women.

So if you're 38, 42 or 45 and something feels off, perimenopause is worth considering. Even if your periods are still regular.

The symptoms most women expect

Changes to your period. Shorter cycles, longer cycles, heavier, lighter, skipped months. Often one of the first signs.

Hot flushes and night sweats. Up to 80% of women get them during the menopause transition. And they don't always pass quickly: in the large US SWAN study, women with frequent hot flushes had them for a median of 7.4 years (Avis et al., 2015). So no, you don't have to just "tough it out" for a few months.

The symptoms that catch women off guard

Sleep problems. Waking at 3am, mind racing, then dragging yourself through the next bursting day. Sleep difficulties become more common as women move through the transition (Kravitz et al., 2003).

Mood changes, anxiety and irritability. The risk of depressive symptoms rises during the menopause transition, even in women who've never had them before (Freeman et al., 2006). Feeling like a stranger to yourself is common, and it's not a character flaw.

Feeling exhausted and overwhelmed. When sleep, mood and hormones all wobble at once, everything feels harder. Work, kids, partner, parents... it all piles up.

Why it's so easy to miss

Perimenopause rarely announces itself. Symptoms come and go, they overlap with stress and busy midlife lives, and many women (and doctors) still think of menopause as something that happens at 50 with hot flushes. That's why so many of us spend years thinking it's "just stress."

Your next step

Start tracking. Write down your symptoms, your cycle and your sleep for a few weeks. Patterns you'd never notice day to day suddenly jump out, and it gives you something concrete to take to your doctor.

In Part 2 we'll look at the sneaky symptoms that almost nobody connects to hormones.

Sources: Pridham, Hayut et al. (2026), Nature Medicine. Avis NE et al. (2015), Duration of menopausal vasomotor symptoms over the menopause transition, JAMA Internal Medicine. Kravitz HM et al. (2003), Sleep difficulty in women at midlife, Menopause. Freeman EW et al. (2006), Associations of hormones and menopausal status with depressed mood in women with no history of depression, Archives of General Psychiatry.