What do periods do to your body?

2 min read

Periods are as different as the people who have them. Mine are irregular, yet each one feels unmistakably familiar: my mood is a bit vague, my pre-menstrual bloating disappears overnight and I suddenly notice my nearest and dearest hiding all the white wine within a one-mile radius. Kelsey, who’s sitting opposite me at Callaly HQ as I type this, feels more of a return to her normal self after PMS and enjoys a sense of “resetting the clock”. We all have such varied experiences of periods, it’d be easy to conclude the whole thing was down to magic rather than science. But sorcery it ain’t: the menstrual cycle is a well-honed system of clever (if sometimes annoying) biological functions. Here’s a brain-to-thighs breakdown of stuff experts confirm is really happening to our bodies when we bleed.

Ur uterus

The obvious place to start is where the blood’s at. At the behest of some hormones called prostaglandins, the uterus cramps up in order to squeeze out the unwanted lining it’s been building up, and that cramping can feel painful (in case you didn’t know…) This pain officially makes it harder to perform cognitive tasks as well, so give yourself a break if it takes longer than usual to work out when to put the garlic bread in if the lasagne’s coming out of the oven at 7:25.

Blood swirls

Bloody brain

While we’re on the subject of using your grey matter, the pituitary gland isn’t hanging about having a long lunch break just because there’s no baby to grow this month. In fact it’s already busy producing follicle stimulating hormone to tell the ovaries to prepare a new egg inside the follicles, in the hopes the next one will get fertilised instead. Poor, hard working pituitary gland. Save it some lasagne.

La-la-la larynx

Hang on, what? Yes, it turns out researchers have discovered that a woman’s voice actually changes slightly during menstruation as a result of hormonal effects on the larynx, becoming lower and hoarser. Men in a study were able to guess a woman’s cycle status correctly 35% of the time just by listening to a recording of her voice – that’s significantly more accurate than if they’d just guessed. We’re not sure if this is really quite awesome or really quite creepy and annoying.


Yes, there’s blood coming out of it. But that’s not the only thing happening to your vulva right now. The pain receptors in and around your genitals change at this point in your cycle, making week one a potentially unwise time to pluck, wax or otherwise mess with your delicate bits. You might also find that your overall pain threshold changes throughout your cycle.

Back to the Futerus

Yes, you read that right. Even your lower limbs aren’t immune to the effects of your period. If you’re getting bad cramps in your uterus, it’s possible for that pain to radiate through the nerves and end up causing you discomfort around your back and upper legs as well. Sheesh, what fun. Is that lasagne ready yet?

Oh, varies! 

So we now know that the ovaries are busy preparing the next egg in their little follicles even as the previous one gets flushed down the toilet (or put in the bin), but we’re not just talking about one egg here. In fact hundreds of follicles start to grow and prep their eggs each cycle, but only the champ of the bunch gets to explode and release its offering. Never mind, those losing follicles might get their time to shine next month.

How does your body feel when you have your period? Any questions about how things work? Send us a DM on Instagram. 💛

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