15/10/2026
Tired, moody, sleeping badly, hair doing something strange and your periods have gone rogue. Is it perimenopause or is it your thyroid?
Honestly, it could be either, and that’s exactly why so many women I see have been going around in circles on this one.
The symptoms overlap so much it’s almost rude. Tiredness, weight changes, brain fog, mood changes, poor sleep, hair thinning and period changes can show up with both. Both are common in midlife, and your thyroid and s*x hormones influence each other, so your body has clearly decided to keep things interesting.
There are some clues though. Hot flushes, night sweats, cycles that are changing, PMS that’s noticeably worse before your period, waking between 2 and 4am and sore breasts tend to point towards perimenopause. Feeling cold, dry skin, brittle nails, thinning outer eyebrows and constipation can point to an underactive thyroid, while feeling hot and sweaty, a racing heart and shakiness can point to an overactive one.
This is where testing helps, but it’s not a magic answer on its own. A TSH by itself may not tell the whole story, so I also look at free T4, free T3, thyroid antibodies and nutrients like ferritin, vitamin D and B12. Hormones swing so much in perimenopause that a single result can mislead, so I read everything alongside your symptoms, your cycle and your history. And because I’m me, we’ll look at your gut too, since it affects thyroid hormone conversion, nutrient absorption and oestrogen clearance.
Yes, it can be both at the same time, and each can make the other worse, because why would it be simple.
You don’t have to just put up with it. Once we know what we’re dealing with, we can layer in the right support, and we can work together to figure out what’s going on. The full breakdown is on the blog, and you can book a consult via the link in my bio, in clinic in Spotswood or via telehealth Australia wide.
https://www.kyliesartori.com.au/blog/2026/10/3/perimenopause-or-thyroid-how-to-tell-the-difference