Signs of perimenopause in your 40s and why they get missed

The signs of perimenopause are well-documented, but they’re also easy to confuse with other health issues. You likely know something’s off—your nights feel restless, your mood switches at a moment’s notice, and your cycle seems irregular—but what if it’s just been a stressful few weeks? Many women aren’t aware that the hormonal shift toward menopause can begin in their late 30s and early 40s. 

This guide will help you identify the signs of perimenopause in your 40s so you know what to ask your doctor and when.

What’s perimenopause, and when does it start?

Perimenopause is the natural transition women go through as they approach menopause. For most women, it begins in their late 30s to mid-40s. Perimenopause generally lasts between four and 10 years. You’ll know you’ve hit menopause itself when you’ve experienced 12 consecutive months without a period.

Symptoms you may experience during perimenopause can include:

• Irregular periods
• Heavier or lighter periods than usual
• Erratic ovulation, affecting fertility
• Mood swings, irritability, and depression
• Low libido
• Hot flashes
• Night sweats
• Increased need to urinate
• Disrupted sleep
• Vaginal dryness

Many of these symptoms are caused by estrogen and progesterone levels rising and falling in unpredictable patterns. They’re two of the most important hormones during pregnancy and for regulating the menstrual cycle.

Why are the early signs of perimenopause so easy to miss?

Women rarely recognize perimenopause in themselves because the symptoms start earlier than they expect. Only 4.3% of women aged 30–35 ask their doctors about menopause, and most don’t arrange an evaluation until their late 50s, even though perimenopause symptoms likely began at around 40.

Hormone levels vary day by day, so a lab test probably won’t be able to tell you whether you’re going through perimenopause. And even if you notice something’s wrong, you might misattribute symptoms to a different health issue. Early perimenopause symptoms like mood changes, poor sleep, and trouble focusing at work also look almost identical to mental health conditions or thyroid troubles. It’s sadly not uncommon for doctors to misdiagnose perimenopause and prescribe antidepressants instead of more effective treatments.

Spot the early signs: A perimenopause checklist

Here’s a few of the most common perimenopause symptoms—including the ones often mistaken for something else first.

Changes to your menstrual cycle

For many women, the first sign of perimenopause is a change to the frequency or intensity of their periods. As estrogen levels rise and fall unpredictably, periods can run shorter or longer than usual, show up heavier or lighter, or skip a month entirely. These are serious changes, but they're some of the easiest to attribute to a stressful month or a lifestyle change.

Sleep disruption and night sweats

Some women experience night sweats during perimenopause, but they’re more common later in the menopause transition. The more telling pattern is you waking up repeatedly or getting out of bed in the morning feeling like you barely slept. Sleep disruption shows up in up to 47% of women during perimenopause, rising even higher the closer they are to menopause.

Mood changes, anxiety, and brain fog

Irritability, anxiety, and brain fog that you can’t seem to shake are all symptoms that stem from unstable estrogen levels. As well as its role in fertility, estrogen helps regulate serotonin and dopamine—the hormones that help manage mood, focus, and emotional steadiness. 

According to a 2025 survey of over 4,000 U.S. women, psychological symptoms are most common during early perimenopause. Since this is usually in women’s late 30s or early 40s, many don’t believe they are old enough to be experiencing menopause symptoms. Instead, it’s common to write them off as conditions like depression, anxiety, or stress.

Low libido, vaginal dryness, and other physical changes

A drop in sex drive and new vaginal dryness are common early signs of estrogen decline, yet many chalk them up to relationship issues or a quirk of aging. The sensitivity of these topics often causes women to hesitate to raise them with their doctor. 

As well as changes affecting intimate areas, women often experience other physical symptoms. Commonly, this includes skin feeling thinner and drier, hair losing density, and energy levels sinking.

Heart palpitations and joint pain

When people experience heart palpitations and unexplained joint stiffness, they often seek tests for cardiac or rheumatology issues. Yet palpitations affect up to 45% of perimenopausal women, and joint pain shows up in around 70%. This is because estrogen helps regulate your heart rate and supports the connective tissue around your joints.

What to do next and when to talk to a healthcare provider

The symptoms and signs of perimenopause vary from person to person and are easy to write off as something else. If any of the symptoms in this post sound familiar, perimenopause is worth asking your healthcare provider about. Since there’s no single test that can confirm a diagnosis, tracking what you’re experiencing for a few weeks can give your doctors more ground to stand on.

If you’re noticing the early signs of menopause, reach out to a clinician at Maven Clinic’s Hormone Care program. Our experts can answer any questions you might have, help you explore treatment options like hormone therapy, and design support around your needs.

FAQ

Can perimenopause cause anxiety even if you’ve never had anxiety before?

Yes. Estrogen helps regulate the brain chemicals behind mood, like serotonin and dopamine. When estrogen levels fluctuate, people with no history of anxiety can experience it. 

Is there a test to confirm perimenopause?

While some tests can hint at perimenopause, hormone levels vary so much from one day to the next that a single test is unlikely to prove anything. Perimenopause diagnosis is clinical, meaning a doctor will establish it based on your age, menstrual history, and symptoms. Coming to your appointment with a few weeks of notes gives your provider far more to work with than any one lab result.

What are the first signs of perimenopause, and can they show up before your periods become irregular?

Hormonal swings can begin years before your cycle visibly shifts. People often notice mood changes, sleep problems, and brain fog first, even while periods stay regular.