Perimenopause fatigue: why you're so tired, and what helps

Perimenopause fatigue is common, but it isn't always hormones. The usual causes, from broken sleep to low iron and thyroid, what helps, and tests to ask about.

By The Change Champions team · Updated 2026-10-01

Part of our guide: Perimenopause sleep problems and night sweats

You wake up tired and stay tired. By mid-afternoon you're running on empty, and by evening even small jobs feel like too much. Coffee doesn't touch it, and a weekend of rest barely helps. If you're in your forties and wondering why you're so worn out, perimenopause fatigue may be part of the answer, but it's rarely the whole story.

This article covers the most common reasons for fatigue in perimenopause, what may help, the tests a doctor may consider, and the warning signs that need prompt attention.

The short answer: perimenopause fatigue is often driven by broken sleep, including night sweats. But heavy periods leading to iron deficiency or anemia, thyroid problems, depression and sleep apnea are also common in midlife and can cause deep tiredness. Because several of these are easy to test for and treatable, ongoing fatigue is worth raising with your doctor.

Why perimenopause fatigue happens

Fatigue is a feeling of weariness, tiredness or lack of energy, as MedlinePlus puts it. In perimenopause, it often has more than one cause at once.

Broken sleep. The Office on Women's Health says low progesterone can make it hard to fall and stay asleep, and that you may feel more tired than usual during the day when your sleep is interrupted. Our guide to perimenopause insomnia covers trouble getting to sleep.

Night sweats. Night sweats can wake you several times a night, sometimes without you remembering. You get fewer long stretches of sleep, and it shows the next day. See perimenopause night sweats for what helps.

Heavy periods and low iron. Periods can get heavier in perimenopause. The CDC says untreated heavy or prolonged bleeding can cause anemia, which can leave you feeling tired or weak. The Office on Women's Health lists fatigue and weakness as very common symptoms of iron-deficiency anemia, along with dizziness, headaches and pale skin. It often develops slowly, so it's easy to blame on a busy life.

Thyroid problems. The Office on Women's Health says one in eight women will develop a thyroid problem during her lifetime. An underactive thyroid can cause tiredness, weight gain, constipation and heavier periods, and thyroid symptoms can be mistaken for menopause.

Depression. Low mood, loss of interest, poor sleep and exhaustion can feed each other. The National Institute of Mental Health says irritability, anxiety, sadness or loss of enjoyment during the menopause transition may be signs of perimenopausal depression. There's more in perimenopause rage, tears and everything in between.

Sleep apnea. The National Heart, Lung, and Blood Institute says women's risk of sleep apnea increases during and after menopause. It says women may have symptoms such as daytime sleepiness, anxiety or depression, and may not snore. Menopause and sleep apnea can share symptoms such as insomnia, headaches and fatigue, which can make sleep apnea harder to spot.

Other causes. MedlinePlus lists many other possible causes of fatigue, including diabetes, heart failure, kidney or liver disease, and side effects of some medicines.

Feeling exhausted in perimenopause is common, but common doesn't mean you should just put up with it. Tiredness is a symptom worth investigating.

What may help with perimenopause fatigue

The most useful step is usually finding the main cause, because the right fix depends on it. While you're doing that, these may help.

Protect your sleep. Keep a steady wake-up time, a cool, dark bedroom and a wind-down routine away from screens. The Office on Women's Health suggests avoiding large meals and alcohol before bed.

Treat night sweats and heavy periods. Both are treatable, and treating them may improve your energy. Our guide to heavy periods in perimenopause explains the options.

Don't start iron on your own. The Office on Women's Health advises against taking iron pills without first talking to your doctor or nurse. A blood test can show whether you need iron, and iron pills can cause side effects such as constipation and an upset stomach.

Move a little every day. The Office on Women's Health suggests regular physical activity, preferably earlier in the day, to support sleep. Start small if you're exhausted. A short walk in daylight counts.

Be careful with caffeine. It's tempting to lean on it, but caffeine in the evening can make it harder to sleep and keep the tired cycle going.

Pace your days. When energy is low, plan demanding tasks for the times you tend to feel best, and let some things go.

Tests your doctor may consider

There's no single test for perimenopause fatigue. Your doctor will usually ask about your sleep, periods, mood, diet and medicines, then decide which tests make sense for you. These are some they may consider.

Blood count and iron tests. The Office on Women's Health says a complete blood count (CBC) and tests of your iron levels can show whether you have iron-deficiency anemia.

Thyroid tests. A blood test for thyroid stimulating hormone (TSH) helps show whether your thyroid is underactive or overactive, according to the Office on Women's Health.

Other blood and urine tests. MedlinePlus says a provider may order blood tests for anemia, diabetes or infection, kidney and liver function tests, and a urine test.

Questions about mood. Your doctor may ask how you've been feeling, to check for depression or anxiety.

A sleep study. If sleep apnea is possible, the National Heart, Lung, and Blood Institute says a sleep study is used to diagnose it.

Bringing a two-week log of your sleep, periods and energy levels makes the appointment more productive.

When to talk to a doctor

MedlinePlus advises making an appointment if you have unexplained tiredness with a fever, weight loss or sweats, or with signs of a thyroid problem such as constipation, feeling cold or weight gain. It's also worth seeing your doctor if tiredness doesn't lift with rest.

Also see your doctor if your periods are heavy. The CDC says signs of heavy bleeding include needing to change a pad or tampon after less than two hours, clots the size of a quarter or larger, or a period lasting more than seven days.

MedlinePlus says to get medical help right away if tiredness comes with confusion, dizziness, blurred vision, passing little or no urine, or recent swelling and weight gain. Call 911 in an emergency, such as chest pain, severe shortness of breath or fainting.

If you have thoughts of harming yourself, call or text 988 (the Suicide & Crisis Lifeline).

Frequently asked questions

Is extreme fatigue a sign of perimenopause?

It can be. Broken sleep and night sweats in perimenopause often leave you tired during the day. But extreme or lasting fatigue can also come from anemia, thyroid problems, depression or sleep apnea, so it's worth getting checked rather than assuming it's hormones.

Why am I so tired even after a full night's sleep?

You may be waking briefly many times without remembering, for example from night sweats or sleep apnea. Anemia, thyroid problems and depression can also cause tiredness that sleep doesn't fix. If rest isn't helping, talk to your doctor.

Can heavy periods make you tired?

Yes. The CDC says untreated heavy or prolonged bleeding can cause anemia, which can leave you tired or weak. Heavy periods are common in perimenopause, so ask your doctor about a blood count and iron tests.

What blood tests should I ask for if I'm always tired?

Your doctor will decide based on your symptoms. Common options include a complete blood count, iron tests and a thyroid test. Tests for diabetes, kidney or liver function may also be considered.

Your next step

For the next two weeks, rate your energy each day from 0 to 10, and note how you slept and whether you had your period. Then take it to your doctor. Our guide to talking to your doctor about perimenopause can help you plan what to say.

To see how tiredness fits with your other symptoms, try our symptom check-in. You may also like our weekly email: calm, practical information, once a week.

This article is general information, not personal medical advice. If you have symptoms that worry you, please speak to your doctor.

Tiredness that doesn't lift with rest, or comes with heavy periods, weight loss, fever or low mood, is worth checking with your doctor. Simple blood tests can rule out common causes.

Sources

Written by The Change Champions team, an independent educational site. Not reviewed by a clinician. How we write and fact-check.