Bloating is the feeling that your tummy is full, tight or swollen, and it is very common. In most people it is caused by ordinary things such as eating quickly, swallowing air, fizzy drinks, certain high-fibre foods, constipation or hormonal changes around a period, and it settles within hours or a day. Bloating that lasts for weeks, keeps coming back most days or comes with other symptoms such as weight loss or bleeding should be checked by a GP.
This guide explains the common harmless causes of a bloated stomach, simple habits that often help and the warning signs that mean it is time to book an appointment.
In short
- Bloating is a feeling of fullness or pressure in the abdomen, and it is sometimes accompanied by visible swelling.
- The most common causes are swallowed air, gas produced when gut bacteria break down food, constipation and hormonal changes.
- Eating more slowly, cutting down on fizzy drinks and chewing gum, and moving after meals often helps.
- A food diary over two weeks can show patterns that are easy to miss day to day.
- Bloating on most days for three weeks or more, or bloating with weight loss, bleeding or a lump, needs a GP appointment.
What is bloating?
Bloating is a sensation of fullness, tightness or pressure in the abdomen. Sometimes your waistband feels tighter by the evening than it did in the morning, and sometimes the belly looks visibly rounder. This visible swelling is called distension, and it often goes together with the feeling of bloating, although either can occur on its own.
The feeling usually comes from gas in the gut, from fluid, or from the gut being more sensitive to normal amounts of gas than usual. In many people, the muscles of the abdominal wall also relax when the gut feels full, which makes the belly push outwards.
What causes a bloated stomach?
Most bloating has everyday causes. Your bowel is home to a large community of bacteria, and InformedHealth.org explains that many of these bacteria help to break down food. When they ferment fibre and some sugars that the small intestine has not absorbed, they produce gas. This is a normal process, but some foods produce more gas than others, and some people notice it more.
The table below shows the most common causes and what you might notice with each.
| Cause | What you might notice | What often helps |
|---|---|---|
| Eating quickly or talking while eating | Burping and fullness soon after meals | Sit down to eat, chew well and put your fork down between bites |
| Fizzy drinks, chewing gum, drinking through a straw | Bloating and burping during the day | Switch to still water and drink from a glass |
| Gas-producing foods such as beans, lentils, onions, cabbage, sprouts | Wind and bloating a few hours after a meal | Increase portions gradually so your gut can adapt |
| Sweeteners ending in “-ol”, such as sorbitol, in sugar-free products | Bloating, wind or loose stools | Check labels on sugar-free sweets and gum |
| Constipation | Fewer bowel movements and a heavy, full feeling | More water, more fibre over time and regular movement |
| The days before a period | Bloating that comes and goes with your cycle | Regular meals, less salt and gentle exercise |
| Large or fatty meals | Heaviness and fullness after eating | Smaller portions and a short walk afterwards |
If your bloating tends to appear soon after meals, our article on bloating after eating looks at the habits most worth changing.
Can certain foods make bloating worse?
Some foods are well known for producing gas. Beans and lentils, onions, garlic, cabbage, broccoli, Brussels sprouts, wholegrains and some fruits contain types of fibre and sugars that gut bacteria ferment. These are healthy foods, so cutting them out completely is rarely a good idea. A better approach is to eat them in smaller amounts and increase them slowly.
Some people find that dairy products make them bloated because they digest lactose, the sugar in milk, less well. Others react to large amounts of wheat or to particular fruits. If you suspect a specific food, keep a food and symptom diary for two weeks rather than cutting out whole food groups. A GP or a registered dietitian can then help you interpret it and, if needed, plan a structured approach.
Why does bloating get worse at certain times?
Many people notice that bloating builds up over the day. In the morning the stomach feels flat, and by the evening it feels tight. This is common and usually reflects the meals, drinks and gas of the day, together with sitting for long periods.
Hormones also play a part. Many women feel more bloated in the days before a period, because hormonal changes affect fluid balance and how quickly food moves through the gut. Our guide to period bloating explains what tends to help during those days. Stress and anxiety can also make the gut more sensitive, so a busy week can bring more bloating even if your diet has not changed.
What simple habits help with bloating?
Small changes often make a noticeable difference. Try eating three regular meals rather than skipping meals and then eating a large one late in the evening. Sit down to eat, chew well and avoid talking with your mouth full. Cut down on fizzy drinks, chewing gum and sugar-free sweets that contain sorbitol or similar sweeteners.
Movement helps the gut to move gas along. A ten-minute walk after a meal is one of the simplest things you can do. Drink enough water during the day, especially if you are increasing fibre. If you have trapped wind, some people find relief from gentle stretches or from lying on their left side for a while; our article on trapped wind relief covers more gentle things to try at home.
Peppermint tea after a meal is a traditional choice that many people enjoy. It is not a treatment, but a warm drink and a quiet ten minutes can be a pleasant end to a meal.
When should you see a doctor?
Bloating is usually harmless, but it can sometimes be a sign of a condition that needs attention. Book an appointment with your GP if you notice any of the following:
- You feel bloated on most days for three weeks or more.
- Bloating keeps coming back, for example more than 12 times a month.
- You have lost weight without trying.
- You see blood in your stools or your stools are black.
- You can feel a lump in your tummy, or your tummy stays swollen.
- Your bowel habits have changed for several weeks, with looser stools or more constipation than usual.
- You also feel full very quickly, have lost your appetite or need to pass urine more often.
Persistent bloating in women, especially over the age of 50, should always be discussed with a GP, because it can be an early symptom of conditions affecting the ovaries. This does not mean bloating is usually serious, but it does mean that it should not be ignored.
Seek urgent help from NHS 111 or A&E if bloating comes with severe or sudden stomach pain, vomiting that will not stop, a high temperature, or if you cannot pass wind or stools at all.
How will a GP investigate bloating?
Your GP will ask about your symptoms, your diet, your bowel habits and your periods, and will usually examine your tummy. Depending on what they find, they may suggest blood tests, a stool test or a test for coeliac disease. For some people, the next step is a referral to a dietitian or a specialist.
It helps to bring your food and symptom diary to the appointment. Write down what you ate and drank, when the bloating started, how long it lasted and anything else you noticed. This gives your doctor a much clearer picture than memory alone.
Frequently asked questions
Why is my stomach bloated every evening?
Gas from the day’s meals and drinks builds up, and long periods of sitting slow the gut down. Regular meals, fewer fizzy drinks and a short walk after dinner often help.
Can drinking water help with bloating?
Yes, enough water helps prevent constipation, which is a common cause of bloating. This is especially important when you eat more fibre.
Is bloating a sign of food intolerance?
It can be, for example with lactose, but most bloating has everyday causes. Keep a food diary and talk to your GP before cutting out whole food groups.
Does stress cause bloating?
Stress can make the gut more sensitive and change how quickly food moves through it. Many people notice more bloating during busy or anxious periods.
When is bloating serious?
Bloating that lasts for three weeks or more, keeps returning most days or comes with weight loss, bleeding, a lump or a change in bowel habits should be checked by a GP. Severe pain or vomiting needs urgent help.
Sources
This article is general information and not medical advice. If you are worried about your symptoms, speak to your GP or pharmacist.