Perimenopause

How Do You Know If You’re in Perimenopause?

By Brenda Chabot, Certified Personal Trainer & Coach · 6 min read

Your periods are doing something new. You’re waking up at 3 a.m. for no reason. You snapped at someone you love over something small, and you’re carrying weight around your middle that wasn’t there a year ago — even though nothing about how you eat has changed.

If that sounds familiar, there’s a good chance you’re in perimenopause. And no, you’re not imagining it, and you’re not “too young.”

I’m Brenda, a certified personal trainer and coach, and I work with women going through exactly this. Here’s the short answer, then the details: you’re likely in perimenopause if you’re in your 40s (sometimes late 30s) and your periods have started changing — along with a handful of the symptoms below. There’s no single test that confirms it, which is part of why so many women get brushed off. Let’s fix that.

First, what’s perimenopause?

Perimenopause is the transition leading up to menopause — the years when your ovaries gradually wind down and your hormones, mostly estrogen and progesterone, stop moving in a smooth monthly rhythm and start swinging up and down instead. Those swings are what you feel.

It’s easy to mix up the terms, so quickly:

• Perimenopause — the transition, when symptoms happen and periods are still coming (even if they’re irregular).
• Menopause — a single point in time: 12 months after your last period. The average age in the U.S. is 51.
• Postmenopause — everything after that.

So if you’re still getting periods but things feel off, perimenopause is the stage you’re in. It commonly begins in your mid-40s, but it can start in your late 30s, and it often lasts around four years — sometimes longer. (If you want the full breakdown, here’s perimenopause vs. menopause.)

The 9 most common signs of perimenopause

You won’t get all of these, and you don’t need to. Most women notice a cluster of three or four. The first one is the big tell.

1. Your periods change. This is the hallmark. They might come closer together or further apart, get heavier or lighter, or start skipping months. Changing cycles are the clearest signal that the transition has begun.

2. Hot flashes and night sweats. Sudden waves of heat, often in the face and chest, sometimes with a flush or sweat. At night they can soak the sheets and wreck your sleep.

3. Sleep that falls apart. Trouble falling asleep, or the classic 3 a.m. wake-up where your brain switches on and won’t switch off. Sometimes it’s the night sweats; sometimes it’s the hormones themselves.

4. Mood swings, irritability, or anxiety. If you feel more short-fused or more anxious than usual — and it doesn’t quite match what’s going on in your life — shifting estrogen and progesterone can be a big part of it.

5. Brain fog. Losing your train of thought, walking into a room and forgetting why, groping for a word that’s normally right there. It’s real, it’s common, and it usually eases.

6. Weight gain, especially around the middle. Many women find the same habits that always worked suddenly don’t, and weight settles around the belly. Falling estrogen and losing muscle both play a role — which is exactly why what you do about it matters (more below).

7. Lower libido and vaginal dryness. Less interest in sex, or discomfort during it. Very common, rarely talked about.

8. Aching joints and more PMS. Stiffer joints, sore breasts, heavier premenstrual symptoms than you’re used to.

9. Heart flutters. Brief palpitations that come and go. Usually harmless in this context — but worth mentioning to your doctor so they can be sure.

So how do you know — is there a test?

Here’s the honest answer, and it’s the part most women aren’t told: there’s no simple blood test that confirms perimenopause.

Because your hormones are swinging day to day, a single blood draw can look “normal” one morning and very different the next. So a test can’t rule it in or out. Doctors diagnose perimenopause mostly from your age, your changing periods, and your symptoms — which means your own experience is the most important evidence there is.

Your doctor might still run bloodwork, but usually to rule out other things that cause similar symptoms, like a thyroid issue. If a provider dismisses you with “your labs are fine,” that’s not the same as “you’re not in perimenopause.” You’re allowed to advocate for yourself.

What actually helps

This is my favorite part, because so much of it is in your hands — and it’s the same foundation whether your main complaint is weight, sleep, or mood.

• Lift something heavy. Strength training is the closest thing there is to a perimenopause multivitamin: it protects the muscle and bone you naturally start to lose, steadies your mood, and helps with the belly-weight shift. You don’t need hours — a few focused sessions a week is plenty.
• Eat enough protein. Most women in midlife eat too little, and protein is what lets you hold onto muscle and stay full. It’s the single easiest nutrition change to make.
• Protect your sleep. A cool, dark room, a consistent bedtime, and easing off alcohol and late caffeine can take real pressure off night sweats and 3 a.m. wake-ups.
• Manage the stress load. Walking, time outside, and simple breathing work aren’t fluff here — they genuinely blunt the mood swings and the cravings.
• Know your medical options. For some women, hormone therapy and other treatments are genuinely life-changing. That’s a conversation for you and your doctor, and it’s worth having rather than white-knuckling through.

None of this has to be complicated. Eat enough protein, train for strength, protect your sleep, and keep it simple enough to actually stick — that’s the whole game.

When to call your doctor

Perimenopause is normal, but a few things deserve a prompt check-in, because they can point to something else:

• Very heavy bleeding, or bleeding that soaks through a pad or tampon in an hour
• Bleeding between periods, or after sex
• Periods that come closer than three weeks apart
• Any bleeding after you’ve gone a full year without one

None of these mean something is wrong — but they’re worth getting looked at rather than waiting.

You’re not losing it — you’re in a new season

If you’ve been feeling like your body swapped out the rulebook without telling you, this is why. Perimenopause is a real, nameable stage, and understanding what’s happening is the first step to feeling like yourself again. The second step is doing the few things that genuinely move the needle.

That’s exactly what my Thrive+40 guides walk you through — the no-fluff plan for eating and training through midlife so you feel strong, steady, and like you again. Start here →

This article is for education, not medical advice. Everyone’s transition is different — talk with your own doctor about symptoms and treatment options that are right for you.