For many people who menstruate, the days leading up to a period bring mood swings, cramps and bloating. You might feel puffy, your jeans may fit tighter or you may notice the scale creeping up a few more pounds. But don’t worry — this isn’t due to weight gain, it’s mostly water retention. 

Period bloating is a completely normal part of the menstrual cycle, but understanding why it happens and what you can do about it can help you feel more in control. In this article you’ll learn more about period bloating, when it occurs and practical ways to reduce the discomfort. 

What Causes Period Bloating? 

A period (also called menstruation) is when blood and tissue from the lining of the uterus (womb) leave your body through the vagina. It usually occurs once a month. This happens because your body prepares for pregnancy and if there’s no sperm present when your egg is fertile, the body sheds the lining. 

Your body goes through four phases: 

• Menstrual: This is when your period starts and the uterus sheds its lining. 
• Follicular: As your period starts, your body prepares for the next cycle by causing the eggs in your ovaries to mature.
• Ovulation: One mature egg is released into the ovary.
• Luteal: The body prepares for pregnancy and if the egg isn’t fertilized, the uterus sheds again.

Bloating during a menstrual cycle is mainly caused by hormonal fluctuations — specifically changes in estrogen and progesterone levels. These hormones influence how your body retains water and regulates digestion. 

Hormonal Shifts

The two primary contributing factors to hormonal shifts are estrogen and progesterone. Estrogen levels rise in the days leading up to ovulation and can cause the body to retain more water. Progesterone — which is responsible for regulating the uterine lining — drops before your period — contributing to digestive issues like constipation and gas. 

People who have anxiety have elevated cortisol levels — this stress chemical affects your estrogen and progesterone causing hormonal shifts. 

Water Retention

High estrogen levels encourage your body to hold on to sodium and water. The fluid is stored in the body’s tissues. Water retention leads to swelling in the hands, feet and abdomen — causing that familiar “puff” feeling. 

Digestive Slowdown

Progesterone can also relax the smooth muscles of your gastrointestinal tract, slowing digestion. Indigestion can lead to constipation, heartburn, bloating and various indigestion issues.

Gas and Gut Sensitivity

Your hormone shift causes period cravings by indicating to your neurotransmitters that it needs sweet or salty foods. But these cravings can affect your gas and gut sensitivity because the excess of sodium can lead to water retention. Changes in diet, cravings — like fats and carbs — and increased gut sensitivity during your luteal phase can lead to excess gas and bloating. 

When Does Period Bloating Usually Occur? 

Bloating typically happens around one week before your period starts and often improves once menstruation begins. This is called premenstrual symptoms, often referred to as PMS.  This corresponds to the luteal phase — when progesterone levels rise, then drop sharply right before menstruation. For some, bloating can persist throughout the period — but it usually resolves by the end of menstruation as hormone levels stabilize. 

How Long Does Period Bloating Last? 

Period bloating varies based on the person and their dietary needs. Most people experience bloating for a few days. Up to 75% of women have bloating issues because of their menstrual cycle. It usually peaks the day before or on the first day of menstruation and then subsides as your period progresses. 

Women have a weight increase of almost a pound because of bloating. This is due to water retention. If you experience prolonged or severe bloating, it may be a sign of another underlying issue like irritable bowel syndrome, food intolerances or a hormonal imbalance like PCOS. It’s always best to consult a healthcare provider if your symptoms are persistent or disruptive. 

Six Steps To Reduce Period Bloating

While bloating is sometimes inevitable and a major cause of discomfort — there are various ways to ease the pain or prevent some outcomes. Here are six steps to reduce period bloating: 

1. Watch your salt intake: Too much sodium can cause your body to hold on to water and cause indigestion. The recommended salt intake is about 1,500mg daily. Try to limit your processed and packaged foods that are high in salt. More than 70% of Americans’ sodium intake comes from packaged foods. Cooking at home allows you to control how much salt you consume. 
2. Stay hydrated: It may seem counterintuitive, but drinking water helps flush excess sodium and prevents your body from holding onto fluids. When your body circulates water, it also helps fluid retention, which will reduce your swelling. 
3. Eat potassium-rich foods: Potassium helps balance sodium levels and supports fluid regulation. Your body uses the mineral to maintain fluid balance and control muscle contractions. Foods that are rich in potassium include bananas, sweet potatoes, avocados and spinach.
4. Avoid carbonated drinks: Soda and fizzy drinks introduce gas into your digestive system because you’re swallowing air— which can worsen bloating. Stick to water, herbal teas, or infused water with lemon or cucumber. These drinks aid in reducing bloating and soothe your digestive system. 
5. Exercise regularly: Movement helps improve digestion and reduces water retention. Even light activities like walking or yoga can help you during your period. If your energy levels are low, try light exercises. If your body can handle strenuous exercises then you should do them to reduce muscle contractions.

6. Limit carbs and sugar: Refined carbs and sugar snacks can cause insulin spikes — which may increase water retention and bloating. Opt for whole grains, fruits and vegetables instead.

From Bloat to Balance — You’ve Got This!

Period bloating is a common and manageable part of the menstrual cycle. While hormonal changes are the root cause, simple lifestyle adjustments — like eating well, exercising, and monitoring your sugar and carb intake — can significantly ease your discomfort. If your symptoms are severe and don’t go away, you should seek medical advice. Else, knowing that bloating is temporary and largely treatable can help you feel more in control of your body.