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    Bloating Before a Period: What Causes It? How Can You Reduce the Swelling?

    Updated 14 February 2022 |
    Published 29 August 2018
    Fact Checked
    Reviewed by Andrei Marhol, PhD, Flo lead medical advisor, Lithuania
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    Bloating before a period can feel really uncomfortable at times. Let’s dive into the nature of this process to learn how to reduce cycle-related swelling.

    Bloating before a period is a common PMS symptom

    The week before your period, you may experience breast tenderness and swelling.

    Symptoms such as bloating, swollen arms and legs, and bags under the eyes can also appear. Swelling and bloating are common symptoms of premenstrual syndrome (PMS) that are caused by water retention. 

    Whether other symptoms of PMS are present or not, water retention is common during this time.

    Bloating before your period: What causes it?

    Water retention associated with PMS can create a bloated, heavy feeling about a week before your period.

    Experts aren’t exactly sure what causes bloating and other symptoms of PMS, but changes in hormone levels and genetics are more than likely major factors.

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    How to get rid of period bloating

    If you’re feeling puffy and bloated, foods that contain potassium, like bananas and dark leafy greens, may help reduce water retention. They do this by counteracting high levels of sodium in the body. 

    Consuming lots of salty foods can make water retention worse. 

    Reducing the intake of refined sugars is also an important step for reducing period bloating. High-sugar foods encourage the pancreas to release a hormone called insulin, which can lead to water retention and bloating.

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    Frequently asked questions about bloating

    Is it normal to experience bloating before a period? 

    Yes, the feeling of bloating just before a period is very common.

    It may occur every month, once in a while, or bloating may never occur at all. Once your period arrives, or a few days into it, the symptoms should disappear. As your period progresses, water retention declines rapidly and the swelling subsides.

    How many days before a period does bloating occur?

    Bloating is a common early sign of PMS. A feeling of bloating may appear about a week before the start of your period. The feeling of bloating might increase and then get better in the first days of your period.

    Is bloating a sign of period or pregnancy?

    Bloating could be a symptom of either PMS or early pregnancy. Bloating before and during a period is triggered by changes in the levels of estrogen and progesterone. Hormonal changes in early pregnancy also cause a feeling of bloating, similar to common symptoms just before the start of your period. Bloating in early pregnancy makes some people feel more snug than usual in their clothes.

    Why You’re Bloated: Cycle or Gut?

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    How do you stop bloating before your period?

    To help limit bloating before your period, you can try the following:

    • Avoid salty foods.
    • Eat potassium-rich foods.
    • Try natural diuretics (e.g., spinach, asparagus, watermelon, cucumber, and garlic).
    • Avoid refined carbohydrates. They can cause an increase in blood sugar levels, which further raises insulin levels and causes the kidneys to retain more sodium.
    • Exercise regularly.

    Your health care provider can provide further advice on other possible remedies for water retention, such as diuretics.

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    Does bloating before a period cause weight gain?

    Bloating caused by water retention or as a symptom of PMS will not result in weight gain. You may feel heavier, but once your period arrives and the bloating disappears, your body should feel normal again.


    Mayo Clinic Staff. “Premenstrual Water Retention: How to Get Relief.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 3 Oct. 2019,

    Tacani, Pascale Mutti, et al. “Characterization of Symptoms and Edema Distribution in Premenstrual Syndrome.” International Journal of Women's Health, Dove Medical Press, 11 Mar. 2015,

    “Premenstrual Dysphoric Disorder (PMDD).” Health Encyclopedia , University of Rochester Medical Center,

    Prior, Jerilynn C., et al. “Fluid Retention over the Menstrual Cycle: 1-Year Data from the Prospective Ovulation Cohort.” Obstetrics and Gynecology International, Hindawi, 8 Aug. 2011,

    Stachenfeld, Nina S. “Sex Hormone Effects on Body Fluid Regulation.” Exercise and Sport Sciences Reviews, U.S. National Library of Medicine, July 2008,

    “PMS Relief.” Office on Women's Health, U.S. Department of Health & Human Services, 16 Mar. 2018,

    Harvard Health Publishing. “Potassium and Sodium out of Balance.” Harvard Health, Apr. 2009,

    History of updates

    Current version (14 February 2022)

    Reviewed by Andrei Marhol, PhD, Flo lead medical advisor, Lithuania

    Published (29 August 2018)

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