What counts as insomnia, and what doesn't
Broken sleep and insomnia aren't the same thing, and the difference changes what helps.
Insomnia symptoms are common. Around a third of people report at least one: difficulty falling asleep, difficulty staying asleep, or waking earlier than they meant to. Insomnia disorder is narrower. It means having at least one of those symptoms along with daytime consequences, at least three times a week, for three months or more, while having enough opportunity to sleep (Psychiatric Clinics of North America, 2023). That last clause matters. If you're in bed for five hours because of work or a relative who needs you, that's sleep deprivation, and it needs a different answer.
Between 4 and 22 per cent of adults meet criteria for insomnia disorder (JAMA Psychiatry, 2024). In perimenopause, reported sleep disturbance runs far higher, somewhere between 40 and 60 per cent (Frontiers in Neuroendocrinology, 2017). One Italian study of 334 healthy women aged 40 to 60 found sleep disorders in 60 per cent before menopause, rising to 67 per cent in perimenopause (Maturitas, 2019).
Worth knowing before you self-diagnose: when researchers asked midlife women separately about “insomnia”, “sleep disturbance” and “restless sleep”, the three answers were so closely correlated that the authors couldn't tell whether the women had shared causes or simply weren't distinguishing between kinds of bad sleep (Sleep Medicine, 2018). Most of us don't, which is exactly why the frequency-and-duration test is more useful than the label.
It's fragmentation, not fewer hours
Here's the finding that reframes it. Hot flushes and night sweats interrupt sleep without shortening it (Obstetrics and Gynecology Clinics of North America, 2018). You're not necessarily getting fewer hours. You're getting the same hours, broken into pieces.
The measurements are specific. Women with menopausal insomnia average around 3.5 hot flushes a night, and roughly 64 per cent of those end in an awakening lasting about 16 minutes (Frontiers in Neuroendocrinology, 2017). Night sweats matter more than daytime flushes: in perimenopausal women, having four or more night sweats a week made frequent insomnia 4.3 times as likely (Sleep Medicine, 2018).
This is also why sleep laboratories keep producing results that seem to contradict how women feel. Studies using overnight monitoring don't consistently find broken sleep in menopausal women. One found peri- and postmenopausal women were less satisfied with their sleep than premenopausal women while showing better sleep efficiency and more deep sleep (Frontiers in Neuroendocrinology, 2017). Your experience isn't wrong. The measure was aimed at the wrong thing. Total hours was never going to show a night broken into six pieces.
If night sweats are the part waking you, our guide to perimenopause night sweats goes into what's driving them, and what your overnight temperature can show covers the signal itself.
What's actually driving it
The honest answer is that it's several things at once, and the popular single-cause explanations don't hold up well.
Falling oestrogen is the usual suspect, and the picture is more complicated than that. In the one study here that measured blood oestradiol directly across 776 women, declining oestradiol was linked to more frequent insomnia at first look, but it dropped out once the researchers accounted for everything else (Sleep Medicine, 2018). Other work does find associations between oestradiol, follicle stimulating hormone and night-time waking (Maturitas, 2019). “Associated with” is as far as the evidence goes. Not “caused by”.
What survived that same analysis was mood. Women reporting depression more than five times a week were 4.8 times as likely to have frequent insomnia, and it was the one factor significantly associated with every sleep outcome the researchers measured (Sleep Medicine, 2018). This runs both ways, which is the part usually missed: insomnia predicts later depression and anxiety, not only the reverse (Psychiatric Clinics of North America, 2023). If you're trying to tell those apart, perimenopause or anxiety works through it.
Does the transition itself add anything, independent of hot flushes and mood? A little. After accounting for health, depression, night sweats and smoking, perimenopausal women were still around 1.4 times as likely to report frequent insomnia as premenopausal women (Sleep Medicine, 2018). Real, but modest, and the same authors concluded that most sleep difficulty in the transition comes from the changing risk factors rather than from menopause acting directly.
One thing that should take pressure off: poor sleep early in perimenopause did not predict poor sleep later in it (Sleep Medicine, 2018). This isn't a door closing behind you.
Why sleep hygiene isn't the whole answer
This is the part that contradicts nearly every article on this subject, and it comes from the largest analysis of insomnia treatment to date: 241 randomised trials, 31,452 people, published in JAMA Psychiatry in 2024. It broke cognitive behavioural therapy for insomnia into its parts and asked which parts do the work.
One thing to be clear about first: this is evidence about insomnia disorder, the three-nights-a-week-for-three-months kind described above. If your sleep is broken for a week because of a heatwave or a deadline, ordinary good habits are still worth having. What the research questions is whether those habits are enough on their own once broken sleep has become the pattern.
Sleep hygiene education did nothing measurable. On the odds of remission it scored 1.01, meaning no detectable effect, and it was equally flat on sleep efficiency, total sleep time, time to fall asleep and time awake in the night. The authors' word for it was “not essential”. Keeping a sleep diary came out inert too. And relaxation scored below neutral, which the authors suggested may be because relaxing in bed keeps you lying there awake longer.
What carried the effect was cognitive restructuring, working on the thoughts about sleep that keep you awake, which was the strongest single component. Then mindfulness and acceptance-based approaches, which are a different thing from relaxation and shouldn't be lumped in with it. Then sleep restriction, deliberately narrowing time in bed to rebuild sleep pressure. Then stimulus control, re-teaching your brain that bed means sleep. And working with a therapist in person, which was the single largest effect in the whole analysis.
Combined, that package produced a number needed to treat of three. Three people go through it, one more reaches remission than would have otherwise. For a behavioural treatment that's a strong number.
Two honest caveats. These trials were in adults with chronic insomnia, not specifically women in perimenopause, though the researchers found no evidence that age, sex or other health conditions changed how well it worked. And sleep restriction in particular is a clinical technique, not something to improvise: done without support it can leave you more tired before it helps. Ask your doctor about a referral for CBT for insomnia, which is the recommended first-line treatment.
When to see a doctor
Insomnia in midlife is sometimes the visible edge of something else, and two of those are easy to miss in women.
Sleep apnoea. Risk rises through the transition: one study found the measure of breathing interruptions increased by about 4 per cent with each additional year in menopause, independently of age and body weight (Psychiatric Clinics of North America, 2023). Using overnight monitoring, 20 per cent of women in one large study had clinically significant apnoea (Maturitas, 2019). The catch is that women with mild apnoea are more likely than men to describe it as insomnia and daytime exhaustion rather than snoring. If you snore, wake gasping, or feel unrefreshed however long you're in bed, raise it.
Restless legs. Recurrent unpleasant sensations in the legs when sitting or lying, an urge to move them, relief on moving, and worse in the evening. Around 9 per cent of women report all four, and it becomes more common in perimenopause (Psychiatric Clinics of North America, 2023).
Also worth ruling out: thyroid changes, chronic pain, reflux, and needing the loo in the night, all common in this age group (Maturitas, 2019). And please see your doctor if low mood is part of this, because treating one tends to help the other. For the wider picture of what else shifts at this stage, see perimenopause symptoms.
anna app doesn't diagnose, and this article isn't medical advice. It's here so you can bring a clearer picture to someone who can.
