12/09/2026
I had a conversation recently in clinic that made me think about something we don't talk about nearly enough. Every month, around menstruation, some women describe feeling almost flu-like:
✨ overwhelming fatigue
✨ feeling hot or feverish
✨ aching or generally unwell
✨ headaches
✨ digestive changes
✨ itchy throat, skin or other allergy-type symptoms
✨ a feeling that their immune system has suddenly gone into overdrive
And then, as that part of their cycle passes, it settles again. So could hormones be involved? Potentially, yes.
Oestrogen and progesterone fluctuate considerably across the menstrual cycle, while inflammatory chemicals such as prostaglandins increase around menstruation. There is also an interesting relationship between reproductive hormones, histamine and mast cells, the immune cells involved in allergic and inflammatory responses.
For some women, the issue may therefore not be that they are genuinely “catching something” every month, but that hormonal changes are triggering or amplifying an inflammatory or histamine-type response. You might hear the informal term period flu, although it isn't a medical diagnosis.
What's fascinating is that we don't actually have a reliable figure for how many women experience this particular pattern. PMS and menstrual symptoms themselves are incredibly common, but cycle-related histamine-type symptoms haven't been studied well enough.
Women can spend years being told that seemingly unrelated symptoms , fatigue, headaches, digestive issues, feeling feverish, itching or just feeling dreadful are separate problems, without anyone asking Does this happen at the same point in your menstrual cycle every month? Keeping a symptom and cycle diary for 2–3 months can be incredibly useful.
And importantly, recurrent symptoms shouldn't automatically be blamed on hormones. Persistent fever, significant throat swelling, breathing difficulties, severe pain or feeling genuinely medically unwell always deserve proper assessment.
Our hormones don't work in isolation, they communicate with our nervous system, immune system, gut and the rest of our body. Sometimes joining those dots changes everything. love, Nina x