Everyone is tired in winter. That’s the problem.
It’s the reason so many women sit in front of me in July having been told, for the third or fourth time, that they’re just run down and it’s the season and everyone feels like this. And they’ve believed it, because it sounds reasonable. It’s cold and dark and they’re going to work before sunrise and coming home after sunset. Of course they’re tired.
But here’s the question I always ask: when the sun came back last year, did you?
If the answer is no – if you can’t actually remember the last time you woke up feeling restored, if summer came and went and the tiredness stayed – then what you’re dealing with isn’t seasonal. It’s just been wearing seasonal clothing.
What normal winter tiredness actually looks like
Your biology genuinely does shift in winter, and some slowing down is appropriate.
Light is the main driver. Your circadian rhythm – the internal clock that tells your body when to be alert and when to sleep – is set primarily by morning light hitting your retina. Less light in, less crisp the signal. Melatonin, the hormone that makes you sleepy, lingers later into the morning. Cortisol, which should spike sharply within thirty minutes of waking to get you up and moving, rises more sluggishly. You feel foggy until mid-morning.
Vitamin D falls too, and it isn’t only a bone nutrient. Vitamin D receptors sit on cells throughout your immune system and your muscles. Levels drop across a Queensland winter more than people expect.
Normal winter tiredness has a shape to it. You’re slower in the morning and better by 10am. A good night’s sleep actually helps. A weekend away restores you. Exercise leaves you tired in a satisfying way, and you feel better the next day, not worse.
What dysregulated fatigue looks like
The pattern is different, and once you know what to look for it’s hard to miss.
Sleep doesn’t fix it. You sleep eight or nine hours and wake up feeling like you’ve been hit by a truck. The tiredness is physical rather than drowsy – your limbs feel heavy, your body feels like it’s carrying something.
Exertion makes it worse for days, not hours. This one matters most. If you go for a walk on Saturday and pay for it on Monday and Tuesday, that’s post-exertional malaise, and it’s a very different animal to being unfit. It’s a sign your mitochondria – the structures inside every cell that convert food and oxygen into usable energy – aren’t keeping up with demand.
Your energy pattern is upside down. Flat at 3pm, wired at 10pm, exhausted but unable to sleep. That’s a cortisol rhythm that has come off its rails, and it points to the HPA axis: the communication line between your brain and your adrenal glands that governs your stress response.
The tiredness came with other things. Brain fog, word-finding trouble, dizziness on standing, new food intolerances, getting sick more often, a heart rate that climbs for no reason. Fatigue rarely travels alone when there’s something underneath it. It started after something. A virus you never quite recovered from. A stretch of prolonged stress. A pregnancy, a surgery, a bereavement. If you can put your finger on a date, that’s clinically useful information.
Why “your bloods are normal” isn’t the end of the conversation
Most women in this position have already had blood tests. Most have been told everything came back fine.
Here’s what’s usually happened. A standard panel checks a handful of markers against reference ranges built to catch disease, and disease is a low bar. A ferritin of 20 is inside the range. It’s also nowhere near enough iron stores to run a body well. A TSH sitting at the top end of normal with no fT3, no reverse T3 and no antibodies tested tells you very little about how much active thyroid hormone is actually reaching your cells.
Then there’s what wasn’t tested at all. Cortisol across the day rather than one 8am snapshot. Organic acids, which show what your mitochondria are actually doing rather than what they theoretically could. B12 in a range that would be considered deficient in Japan and normal here. Homocysteine. RBC magnesium.
Normal is not the same as optimal, and neither is the same as well.
What to do with this
If your fatigue has the shape of the second pattern rather than the first, three things are worth doing before winter ends.
Get morning light on your face within an hour of waking, outside, for ten minutes minimum, no sunglasses. It’s free and it’s the single most effective thing you can do to re-anchor a drifting cortisol rhythm.
Stop pushing through. If exertion sets you back for days, the fix isn’t more discipline – it’s pacing, and getting the underlying energy production working before you ask more of it.
Ask for the right tests, not more of the same ones. Ferritin with iron studies. A full thyroid panel including fT3, reverse T3 and antibodies. Vitamin D, B12, zinc, homocysteine, hs-CRP.
Winter tiredness lifts when the light comes back. If yours didn’t lift last summer, it isn’t waiting on the weather. It’s waiting on someone looking properly.
If that’s you, I offer a 20-minute Discovery Call as a starting point – a chance to talk through what’s actually going on and whether a root-cause approach is the right fit.
You can book directly through my website at www.drshelleycavezza.com.au.
– Shelley
📍 Sunshine Coast | 🌐 drshelleycavezza.com.au 📞 0419 821 666 | ✉️ info@drshelleycavezza.com.au
This post is for educational purposes only and is not a substitute for personalised medical advice. Please consult your healthcare professional before making significant changes to your health routine.
