Period bloating: Why it happens and how to treat it

One of the most frequent menstrual symptoms, 75% of women experience bloating.
Written by
Kate Evans
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Last updated on
July 18, 2024
min read
Period Bloating: Why It Happens and How to Treat It | Kin Fertility
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Aunt Flo is coming for a visit. Shark week is on its way. You're surfing the crimson wave, à la Cher Horowitz.

However you refer to it — and whether or not you keep a symptom diary — there are many ways you can tell that start of your period is imminent. You experience mood swings that you can't always explain away. Breast tenderness, which prevents you from doing any physical activity unless the girls are strapped down solid. A pesky pimple or 2 makes itself known [1].

And then there's bloating — which up to 75% of women experience both before, and after, their period [2]. It's one of the most frequent menstrual symptoms, one study of university nursing students in Spain found it was the most prevalent, affecting 87.3% of the 229 students surveyed [3][4].

Or, as another study put it, the menstrual cycle has an "aggravating influence" — aggravating is right — in females suffering from bloating; this is something that is "frequently observed clinically" [5 ].

So needless to say, if you're currently looking down at a bloated belly, you aren't the only one experiencing it — or the only one wanting to know how to treat it.

Why does period bloating occur?

Like most everything related to our cycle, the reason women experience bloating is, unsurprisingly, due to hormone levels — and, in turn, sex hormone effects.

You've most likely noticed your weight fluctuates throughout your period, and it feels like you've gained weight as you get nearer to the starting time.

This fluctuation in body mass is due to shifts in fluid retention — bloating — at certain phases of your cycle; it can also be due to gas and digestive backup (poop) [2]. It's "partially attributed" to the hormonal changes throughout. [6]

Getting specific, it comes down to your progesterone and estrogen levels. Estrogen causes water retention, and when it rises — and within your body, you experience a hormone progesterone fall — that's when you bloat. And, you just happen to have more going on in your uterus pre-period; it's like someone grabbed a remote and increased the volume (not that kind of volume, though). [2]

TL; DR: it's a combination of high estrogen, low progesterone, and inflammation [7].

These 2 hormones also interact with your digestive system, causing intestinal gas. And in addition to this — yes, your hormones are really mucking you about here — the estrogen receptors in your digestive tract affect visceral sensitivity — the actual feeling of bloating. [2]

It's not only those who are assigned female at birth that experience bloating. Trans women and transfeminine people who undergo hormone replacement therapy often report menstrual symptoms that occur on a cyclical basis — and yep, that includes bloating [8].

What does bloating feel like?

One definition of bloating is "a feeling of increased abdominal pressure, that may or may not be accompanied by objective abdominal distention." Meaning, you might feel bloated, but you might not look it — no visible enlargement of the waist, or swollen abdomen [6].

Expanding on that, the feeling could also be that of tightness or fullness in your belly. And the feeling of bloating can range from mildly uncomfortable, all the way to intensely painful [2].

But that's just the physical feeling.

Period bloating affects you mentally, too. One book, interviewing women about their periods, reported that the majority of those who took part had negative feelings toward their bodies "and by implication their very selves" when they had premenstrual syndrome [8].

Words like "sluggish", "disgusting" and "gross" were all used as self-descriptors and were attributed to these perceived physical PMS symptoms — yep, like bloating.

It wasn't that period bloating managed to negatively affect self-confidence, it "annihilated" it. And, from that, period bloating may result in having to alter clothes to accommodate bloating — think the feeling when you pass over all your sexy undies for your period undies, then times it by a thousand.

How long does period bloat last?

So remember how the feeling of bloating can range quite significantly? Well, it turns out the timings of period bloating also range quite significantly.

Looking at total body water retention throughout an entire cycle, one study found fluid retention saw a gradual rise from 5 days prior to ovulation (and ovulation is generally at day 14 of your cycle), all the way to the start of your period. Then, it peaks on day 1 of your period [9].

To decrease water retention? Wait until the end of your period, that's when it reaches its lowest point — according to this specific study.

This is where period bloating can qualify as premenstrual syndrome, as to do so, PMS symptoms "must" occur during the 10 days before your period, and have to "disappear" either during or shortly after, your bleed [7].

Other organisations say many women experience period bloating 1-2 days before their period starts [6]; some claim it's a "short-lived" occurrence during the follicular stage of menstruation — from the first day of your period, for about 13-14 days, until day 1 of ovulation [10].

And yet again, other sources say period bloating (and the discomfort that comes along with it) can sometimes develop during ovulation [5].

So we're looking at any time between 5 days or 1 day before your period, but it could end when your period ends, or it could occur any time up until you ovulate, or you could be bloating while you ovulate.

At what point in your period are you the most bloated?

When you experience your worst bloating depends on what cycle from the above you fall into. Your period bloating could be directly correlated with your premenstrual syndrome or premenstrual dysphoric disorder, or it could be more influenced by ovulation.

However, if you are the type of person who noticed period bloating in the 5 days prior to the start of your actual period, then it's likely you'll feel significantly more bloated — and you'll feel heavier — while menstruating. This is regardless of whether or not you're on a contraceptive pill.

Emphasis on the word feel here, as it is not actually accompanied by "shifts in body composition results" [9].

What are ways to help get rid of period bloating?

Firstly, if you are concerned about your period bloating (and other PMS symptoms) — and it's having a significant impact on your well-being — then have a discussion with your doctor or another medical professional that specialises in women's health. It could be a sign of a more serious health condition like IBS, or endometriosis.

Whether you want to improve period bloating, reduce period bloating, relieve period bloating or another umbrella phrase altogether, here are a few different things you can do.

Healthy foods

Start simple — eat a balanced diet. More fruits and vegetables, as well as lean protein, can help ease period bloating [11]. Make sure to incorporate dark leafy greens, like kale and silverbeet [12].

Try a probiotic supplement

Supplements can be helpful with bloating. An effective digestive health supplement should contain pre and probiotics, fibre, and digestive enzymes to ensure your gut’s nutritional needs are being met.

Gut health is important for more than just digestion, it also supports your mental health through the gut-brain axis. That's why our formula contains patented probiotics that promote mental well-being, to look after your body and mind.

Exercise regularly

Regular aerobic exercise — walking, swimming, running, cycling — can help lessen common symptoms of PMS [7]. In addition to this, regular exercise that focuses on strengthening your core can help combat period bloating.

When you exercise regularly, it also helps prevent water retention and keeps those bowels moving [2].

In addition to regular exercise, focusing on relaxation techniques — breathing exercises, yoga, meditation — can help improve PMS symptoms.

Prioritise sleep

Yep, one thing that can help reduce bloating — and might target other symptoms of PMS while you're at it — is good old sleep [13]. PMS can cause sleeping problems; it's beneficial to focus on getting into a good sleep routine prior to your period starting.

Yep, that means canning your nightly bedtime scroll through TikTok.

Reduce caffeine and alcohol

Ever gone out-out drinking in a tight dress, only for that dress to seem waaaaay tighter at the end of the night, than at the beginning? Alcohol. If you're already bloating, well, you don't need to add alcohol bloat to the mix.

And we're sorry to tell you this about your best friend every morning, but caffeine can also contribute to an achy, bloated feeling. Sweet and carbonated drinks aren't your friend, either [14].

And it may seem a bit of a paradox to drink more water when it's water retention you're seeming to target, but if you drink plenty of water a day — looking at 2L here — it can help reduce period bloating and aid your digestive tract [12].

Our body needs to stay hydrated and healthy at the best of times and this also aids in reducing bloating.

Decrease salt intake

Yes, salty foods are fantastic and taste delicious. But, very sadly, salt causes water retention, and this can lead to — you guessed it — bloating [13]. Do your best to avoid salty foods (looking at you in particular, processed foods), and try not to add too much salt to meals you cook for yourself.

Image credit: Getty Images

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