Perimenopause usually starts years before your periods stop

Your period still comes, just not on the schedule it used to keep. You wake at 3 a.m. for no reason. Your patience is shorter than it was a year ago. Everyone around you, including you, has been calling it stress.

Stress is real. But this particular combination, arriving in your late 30s or 40s, has another name worth ruling in or out: perimenopause, the transition before menopause.

It often starts while your periods still come

Many people picture menopause as the moment periods stop. The change usually starts well before that. Mayo Clinic says perimenopause changes often begin sometime in your 40s, and some people notice them as early as their 30s or as late as their 50s. Cleveland Clinic puts the range at as early as your mid-30s or as late as your mid-50s.

It isn't a short phase either. Cleveland Clinic gives the average length as about 4 years and says it can last up to 8. Menopause itself most commonly arrives between 45 and 55 years old, according to MedlinePlus. Add those together and many people spend a good part of their 40s in the transition without anyone naming it.

Why it's so easy to miss

The early signs are ordinary on their own. Mayo Clinic lists irregular periods, hot flashes, sleep problems and mood changes. Cleveland Clinic adds night sweats and mood shifts. Any one of those has a dozen everyday explanations, and most people in their 40s are carrying work, kids, aging parents or all 3.

A cycle that's irregular rather than absent is the easiest sign to explain away. It still comes, so it doesn't feel like a change. And because the signs arrive gradually, there's rarely a single day that makes you stop and ask.

Some of the same signs can come from your thyroid

This is the part that's worth checking rather than assuming. An underactive thyroid can look a lot like early perimenopause. The NIDDK's list of common hypothyroidism symptoms includes fatigue, weight gain, depression, and heavy or irregular menstrual periods.

That overlap is why a careful workup for perimenopause symptoms looks at more than one system. Our women's hormone panel covers estradiol, progesterone, FSH, luteinizing hormone and testosterone alongside a thyroid panel and general metabolic markers, so the 2 can be told apart instead of guessed at.

Track 2 cycles before your visit

The most useful thing you can bring to an appointment is a short record. For your next 2 cycles, write down the day each period starts, how heavy it is, any nights you wake hot or sweating, how you slept, and any days your mood felt out of proportion to what was going on.

Then look at it. If your cycle length is moving around, and the sleep and mood changes cluster around certain days, you've given your provider a pattern instead of a feeling. Patterns are what make a plan possible.

Naming it early is what gives you options

Perimenopause isn't a disease to be cured. It's a transition, and how it affects you is individual. Knowing you're in it means the sleep, the mood and the cycle stop being separate mysteries, and you can talk with a provider about what fits your symptoms and your history.

The earlier it has a name, the longer you have to make choices about it on purpose.