Bloating is very common and usually linked to food, gut habits or your cycle. Learn the main causes, what brings relief and the warning signs that need a doctor.
The short answer
Most bloating comes from gas, constipation, eating quickly, fizzy drinks, certain foods, or hormone changes before a period. It usually eases within a day. Bloating that is there most days for three weeks or more, or that comes with weight loss, bleeding or changes in bowel habit, should be checked, because in a small number of women it can be a sign of ovarian cancer.
Common causes
- Your cycle: progesterone in the second half of the cycle slows the gut, and water retention peaks just before a period.
- Constipation: stool backing up traps gas.
- Foods that ferment: beans, onions, garlic, wheat, some fruits, sugar alcohols (sorbitol, xylitol) and, for some, dairy.
- Swallowed air: eating fast, chewing gum, fizzy drinks.
- Irritable bowel syndrome (IBS): recurring belly pain with bloating and changes in bowel habit; more common in women.
- Coeliac disease: bloating, diarrhoea, tiredness and low iron.
- Perimenopause and GLP-1 medicines: both can change digestion.
The short version
What brings relief
- Eat slowly and have smaller, regular meals
- Increase fibre gradually and drink enough water to keep bowels regular
- Walk after meals
- Cut back on fizzy drinks, gum and sugar-free sweets
- Keep a two-week food and symptom diary, including cycle days
- Ask a pharmacist about simethicone, or peppermint oil capsules for IBS
- If you suspect IBS, a dietitian can guide a short low-FODMAP trial; don’t cut out whole food groups long-term on your own
Bloating that needs a doctor
See a doctor if bloating is persistent, meaning most days for three weeks or more, especially if you are over 50 or have any of these:
- Feeling full quickly or loss of appetite
- Pelvic or belly pain
- Needing to pee more often or urgently
- Unexplained weight loss or tiredness
- Changes in bowel habit or blood in your stool
- Bleeding after menopause or between periods
These symptoms are much more likely to have a common cause, but persistent bloating is one of the main early signs of ovarian cancer, so it deserves a check, which may include a blood test (CA-125) and an ultrasound.
Frequently asked questions
Why am I so bloated before my period?
Hormone changes slow digestion and cause water retention in the days before a period. It usually eases once bleeding starts.
How do I get rid of bloating fast?
Walk, avoid fizzy drinks and gum, eat slowly, and ease constipation with water and fibre. Simethicone may help gas.
When is bloating serious?
When it happens most days for three weeks or more, or comes with weight loss, bleeding, early fullness or bowel changes.
Can bloating be a sign of ovarian cancer?
Persistent bloating is one of its early signs, though it is far more often caused by something common. Get it checked if it doesn’t go away.
Spot your pattern
Bloating that follows your cycle is easier to discuss with a clinician when you can show a pattern. The free PCOS Starter Kit includes a cycle and symptom tracker.
