Ask An Adult: What Happens To My Body The Week Before My Period?

So what actually happens to our bodies the week before a period to call forth this hideousness?Illustration by Katie Turner

Ask An Adult: What Happens To My Body The Week Before My Period?

by Victoria Joy |
Published on

Periods are a pain in the arse. I mean, not literally, but given the amount of discomfort, hassle and grimness they serve up, I don't know a single woman who considers her monthly cycle a walk in the park.

Even if you're one of those #blessed bitches whose monthly blood splatter only calls for a couple of days worth of super-light tampons, chances are the other weapons out menstrual cycle holds in its arsenal - bloat, migraines and the constant urge to crap - make you miserable. In fact, according to the National Association for Premenstrual Syndrome, it's estimated as many as 30% of women experience moderate to severe symptoms of PMS.

So what actually happens to our bodies the week before a period to call forth this hideousness?

It's a hormonal shitstorm, truth be told - we're looking at you, progesterone. Which is why we need consultation gynaecologist Nick Raine-Fenning to shed some light on the matter...



When your stomach becomes the human body equivalent of a puffa fish? Yeah, that. Although it may feel like you're full of air, it's actually water retention, most commonly occurring in the abdomen and breasts. The drop of hormone progesterone just before your period causes excess fluid to build up in the body, pushing the skin to stretching point and producing aches and pains. Ironically, upping your water intake can help relieve symptoms, as it helps the body flush out water needlessly hanging around. And as much as you might want to drown your period sorrows in a double dose of Hendricks and tonic, avoid – alcohol only serves to dehydrate you which has the opposite effect of beating water retention.

Toilet trauma

Whether it's spending half of your working day in the ladies thanks to diarrhoea or constipation, or desperately trying to avoid embarrassing gassy situations on your commute, the onset of your period plays havoc with your bowel movements. This less-than-preferable toilet trouble can be down to a number of things; first there's prostaglandins, hormone-like compounds responsible for triggering period cramps, which have been found in high concentrations among women who struggle with diarrhoea around that time of the month. As if that isn't enough, the changes in estrogen and progesterone interfere with bacteria in the gut – messing up the digestive process; cue the heinous stench coming from your toilet cubicle.

The hunger

Behold, the majesty of mac and cheese. And once you've ploughed your way through that, there's a Sara Lee black forest gateau with your name on it. While we can't help you explain away an insatiable desire for stodgy carbs and sugary treats all month, there is legit science behind the inevitable calorie binge the week before your period. A natural spike in the hormone cortisol stimulates your appetite, making your body cry out for Pringles when it might otherwise be happy with a pear. Then there's the fact that PMS also causes a drop in serotonin, which ups your carb cravings because the body naturally converts carbohydrate to serotonin. Let the gorging commence.

Brain fuzz

Staring at your computer and willing it to write that work report is all well and good, but miracles don't happen. Which is yet another reason why the week before your period is lame, because that oestrogen drop has been shown to trigger a decrease in mental clarity too. Best to try to reschedule any exams or assessments in that case. But get this; when oestrogen levels hike back up during ovulation, women seem to enjoy a boost in verbal skills, unwittingly nailing power point presentations across the land.


According to official numbers, more than half of women who get migraines suffer around the time their period hits, and head pain at this time of the month is said to be much more intense. Why? It's thought to be caused by the natural fluctuation in your oestrogen levels, which occurs immediately before the beginning of your menstrual flow. This thinking is supported by the fact that some oral contraceptive pills have been found to trigger migraines, even if they actually increase oestrogen – it seems any fluctuation in this hormone, whether that's making levels higher or lower, can cause a pounder.

All the tears

Mood swings might just be the biggest stereotype of PMS symptoms, but that stereotype exists for a reason. Changes in hormones, as well as slight alterations in the chemical processes of the brain, are believed to trigger emotional and psychological reactions in individuals, with many women reporting a tendency to cry or feel sadness.


It's a hormone game again. In the 7-14 days before your period, the body's level of the sex hormone estradiol falls but testosterone remains high, which gives rise to an increase in the production of the skin's sebaceous glands. It means your skin is producing more natural oils on a daily basis, particularly in those people who tend to have oily skin in the first place, and so the likelihood of congestion and spots becomes higher at that point in the menstrual cycle.


Low energy is a given for many women in the lead-up to their period but there's little evidence that the body actually dips into its power reserves more than normal during this time. It's more likely that because of some of the other symptoms listed above - like headaches, bloating and migraines – your usual sleep cycle is disrupted and you don't clock up the amount of rest your body is used to. In addition, rising and falling levels of oestrogen increases body temperature, which has a direct impact on your natural sleep cycle, and the desire to turn to calorie-heavy, comfort foods is likely to play a role in increasing feelings of lethargy and sluggishness.

Like this? Then you might also be interested in:

Awful Period Stories To Haunt You For Days

A Quarter Of Men Think They Have 'Man Periods'. LOL, Etc

France Steps Up And Cuts Their Tampon Tax

Follow Victoria on Twitter @spreadingthejoy

This article originally appeared on The Debrief.

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