You fall asleep fine. Then you wake at 3am with your heart racing and your mind racing, and there is nothing specific bothering you. You have never been a bad sleeper. Now you wake up tired, wired and furious about everything, especially your sleep.

Dr Mayoni Gooneratne, PHC's Chief Functional Medicine Officer, sees sleep as one of the hallmark changes of perimenopause. If perimenopause had a signature, she says, it would be "falling asleep fine, waking up at 3 with your heart racing, your mind racing."

If that is you, she wants you to hear this first: "I just want you to know that you're not broken." Your physiology is doing something predictable, and once you understand it, you can start to do something about it.

What perimenopause does to your sleep

Two hormonal shifts are at work.

Progesterone falls and fluctuates. Progesterone has a genuinely calming, sleep-promoting effect through its action on GABA receptors, your brain's own braking system. In Dr Gooneratne's words, "Less progesterone means a less effective brake." You spend more time in lighter stages of sleep, which means more awakenings and more of that wired but tired feeling.

Oestrogen declines. This changes how your body regulates temperature. Your brain's thermostat becomes, as she puts it, "really trigger happy." A small overnight rise in temperature that you would once have slept through now wakes you up. Stress and cortisol can make this more noticeable.

So the 3am wake-up is often a temperature event that feels existential.

Why midlife makes it harder

There is more to it than hormones. Midlife is, for many women, the peak of responsibility for everything and everyone, and the peak of rumination. It is often the first time anxiety really takes hold. Perimenopause amplifies anxiety through hormonal pathways, and you have a brain that is sleeping more lightly. Dr Gooneratne calls that whole combination brutal.

Many women tell her their cortisol is broken. The truth, she says, is that it is rarely that simple, and it is not a straight line from one cause to one effect.

What a standard appointment can miss

The typical approach to midlife insomnia is a sleeping tablet or sleep hygiene advice. If you have woken at 3am every night for a month, she says, that advice is "like being asked to tidy a house fire."

Instead, Dr Gooneratne takes a thorough sleep history as part of a full assessment. She looks at:

  • Signs of sleep apnoea. Do you snore? Your partner may know better than you. Do you wake unrefreshed even after a full night in bed? Sleep apnoea is under-recognised in women because the picture people look for is a middle-aged man who snores loudly. "A woman's apnea looks like insomnia and anxiety, it's not snoring." A sleep study can change management completely, and it can now be done at home, with 30 days of data to review together.
  • Iron stores. "Low ferritin is a really, really common cause of restless legs and fragmented sleep."
  • Thyroid function.
  • Caffeine and alcohol timing.
  • Overnight blood sugar. A dip in blood sugar can wake you around midnight feeling jangly and adrenalised.

What helps with perimenopause sleep

Dr Gooneratne works through these roughly in this order.

Understand the whole picture. That includes your genetics, past trauma, gut health, relationships and stress.

Treat night sweats if they are the problem. If night sweats are disrupting your sleep, it is time to talk about body-identical hormone replacement therapy. Alongside that, cool your bedroom and choose lighter bedding and breathable nightwear. Unglamorous, but effective.

Cognitive behavioural therapy for insomnia (CBT-I). This means structured CBT for insomnia, not just a relaxation app. It has "the strongest evidence of anything we have for persistent insomnia," and Dr Gooneratne notes it is available on the NHS through self-referral. "I'm distressed at how few women are offered that."

Caffeine and alcohol. If you drink caffeine after noon, she says, "that is half of your experiment done for you." Alcohol may help you fall asleep, but it repays you at 3am.

If sleep is also affecting your memory and focus, read perimenopause brain fog: what is happening and what helps.

Frequently Asked Questions

Why do I wake at 3am in perimenopause?

Falling progesterone means a less effective brake on the brain, so you sleep more lightly and wake more often. Falling oestrogen makes your temperature control more sensitive, so a small overnight rise in temperature can wake you. Stress, cortisol and a racing mind make it more noticeable.

Is my cortisol causing my sleep problems?

It can play a part, as stress and cortisol can make temperature-related waking more noticeable. But Dr Gooneratne says it is rarely as simple as broken cortisol. Hormones, temperature, anxiety, life load and other factors usually work together.

Will HRT fix my sleep?

If night sweats are what is disrupting your sleep, body-identical HRT is worth discussing with your doctor. It works best alongside the basics: a cool bedroom, lighter bedding, breathable nightwear, caffeine before noon and less alcohol.

Do I need a sleep study?

It is worth considering if you snore, if a partner has noticed you snoring, or if you wake unrefreshed despite a full night in bed. In women, sleep apnoea often looks like insomnia and anxiety rather than loud snoring. A sleep study can now be done at home.

Is it OK to keep using sleeping tablets?

Dr Gooneratne's answer is no, not as a long-term solution. They do not address why you are waking. If you have been prescribed sleeping tablets, talk to your prescriber before making any changes.

Can low iron affect my sleep?

Yes. Low ferritin, a measure of your iron stores, is a common cause of restless legs and fragmented sleep, which is why it is worth checking.

What is CBT for insomnia?

CBT for insomnia (CBT-I) is a structured talking therapy that targets the thoughts and habits that keep insomnia going. It has the strongest evidence of any treatment for persistent insomnia and is available on the NHS through self-referral.