You're Not the Only One Awake
I don't think I am unusual. I think I am, if anything, entirely ordinary, and that is rather the point. Perimenopause can begin as early as your late thirties, and yet we talk about it in whispers, usually only once we are already deep inside it and looking for someone who understands.
You wake at three in the morning for no reason you can name, doing the sums on how little sleep you'll be running on tomorrow. The days that follow pass in a kind of autopilot: functioning, ticking through the list, without ever quite feeling like you're in the room.
I don't think of this as decline. I think of it as a second set of instructions arriving for a body I already know how to run — and once I stopped treating the exhaustion as a personal failing, everything else got easier to look at clearly.
What it actually is
Perimenopause is the transition into menopause, when oestrogen and progesterone begin to fluctuate before settling into decline. Symptoms can begin in the late 30s to mid-40s, on average four to eight years before periods stop altogether. Menopause itself — twelve months without a period — arrives, on average, at 51. There is no single test that marks the start; for most women it's a pattern that builds gradually until, looking back, the shift is obvious.
Neuroscientist Roberta Brinton first made the case, in a landmark 2015 paper, that perimenopause is best understood as a genuine neurological transition rather than a purely reproductive one — the brain, not just the body, adjusting to a new hormonal landscape, not unlike puberty but running in reverse. More recent PET-imaging work from Lisa Mosconi at Weill Cornell has shown this directly: as oestrogen falls, measurable brain energy metabolism drops with it, particularly in the regions that govern memory. Oestrogen acts directly there, which is why brain fog and low spirits are physiological, not imagined.
A global study by Mayo Clinic and the health app Flo, surveying more than 17,000 women across 158 countries, found that among women over 35 who identified as being in perimenopause, 95% reported exhaustion and 93% reported fatigue — far higher than those reporting hot flushes, the symptom most people still associate with it first.
It's easy to mistake for simple overload, especially if your days are already full. There is a difference, though, between being tired because life is full and being tired in a way that sleep doesn't fix. If the exhaustion, the fog, or the flatness persist regardless of how well you're managing everything else, it's worth asking whether your hormones, not your schedule, are the cause.
Signs of Perimenopause
- Irregular periods — heavier, lighter, longer, or further apart
- Disrupted sleep, including waking in the night
- Fatigue and low-grade exhaustion
- Brain fog and word-finding difficulty
- Hot flushes and night sweats
- Mood changes — irritability, snapping when you'd normally let it go
- Joint and muscle aches
- Changes in body shape and weight distribution
- Lower libido and changes in intimacy
The case against treating everything as hormonal
It would be wrong to pretend this is a settled subject. A 2002 study linking HRT to breast cancer, later shown to be flawed, spooked a generation of doctors into under-prescribing for two decades — and many clinicians argue women are still paying for that caution now. The pendulum has also swung the other way, though. Following a run of high-profile controversies over private menopause clinics prescribing HRT at well above licensed doses, senior figures in British menopause medicine — including the chair of the British Menopause Society — have warned that testosterone and HRT are increasingly being sold as a fix for symptoms that may have nothing to do with hormones at all, and that patients are being left with the impression they need treatment rather than may benefit from it.
Both things are true at once: perimenopause is still under-recognised and under-treated, and it is also, in some corners, being over-attributed and oversold. Neither excuses the other.
Where I've landed
What nobody warns you about is how much of this is not really about the body at all. The symptoms are real and worth treating properly. Underneath them, though, sits something quieter: a kind of grief for the version of yourself that used to move through the world without having to think about it.
Small Things That Help
- Protect sleep like an appointment — same wake time, cool dark room, no negotiating
- Strength train twice a week; muscle mass protects both metabolism and bone density through this transition
- Cut back caffeine and alcohol in the afternoon — both worsen night waking
- Track your symptoms for a cycle or two before your GP appointment — patterns are easier to treat than vague complaints
None of this is about pretending the changes aren't happening. Understanding what's going on is the first step. If your symptoms are disrupting daily life, it's worth seeing your GP or an endocrinologist rather than managing alone. Diagnosis is largely clinical, based on your age, symptoms and cycle changes, but a doctor may also run bloods for FSH (follicle-stimulating hormone), oestradiol and thyroid function — useful for ruling out other causes, even though hormone levels fluctuate too much during perimenopause to be conclusive on their own. From there, help takes many forms: HRT; targeted supplementation (magnesium, vitamin D, omega-3s are the ones with the best evidence); and the basics that are easy to dismiss and hard to argue with — protein at breakfast, strength work, and sleep treated as non-negotiable.
A Note from Mrs H
The changes are real, and they deserve to be named properly rather than minimised or oversold. Whatever this stage is asking of you, it is worth listening to — and worth getting proper help for, from someone weighing your case rather than reaching for a default. Whatever you're feeling right now, at three in the morning or in the middle of an ordinary afternoon, you are not the only one awake.
— Mrs H