Stomach Pain: Causes, Types & When to Worry
Explore the most common reasons for stomach pain, learn to identify the type by location, and know when to seek help.
Upper Stomach Pain
Pain in the upper abdomen (above the belly button) is most commonly caused by acid reflux, gastritis, or indigestion. Acid reflux causes a burning sensation behind the breastbone, often worse after eating or lying down. Gastritis — inflammation of the stomach lining — causes gnawing pain, nausea, and feeling full quickly. It's often triggered by NSAIDs (ibuprofen, aspirin), alcohol, or H. pylori bacteria. Treatment includes eating smaller meals, avoiding trigger foods (spicy, acidic, fatty), not lying down within 3 hours of eating, and over-the-counter antacids. If symptoms persist for more than 3 weeks, your GP may prescribe a PPI (proton pump inhibitor) like omeprazole and test for H. pylori with a simple breath test.
Lower Stomach Pain
Lower abdominal pain has different causes depending on location. Central lower pain is often caused by IBS, constipation, or bladder infections. Left-sided pain may indicate diverticulitis (more common over 50) or constipation. Right-sided pain — especially if severe and sudden — could indicate appendicitis. It typically starts as pain around the belly button that moves to the lower right side after a few hours and gets worse. Contact NHS 111 or ask for an urgent GP appointment as soon as tummy pain moves to the lower right or is steadily getting worse — you do not need to wait for a fever. Pain can be less typical in pregnancy, in young children and in older people. In women, lower abdominal pain can relate to menstrual cramps, ovulation pain (mittelschmerz), endometriosis, or ovarian cysts. For men, consider testicular torsion if lower abdominal pain is accompanied by testicular pain. IBS is common and causes cramping, bloating, and alternating diarrhoea/constipation, often triggered by stress and certain foods.
Bloating and Gas
Bloating is one of the most common digestive complaints. It's usually harmless and caused by eating too quickly, swallowing air, or eating gas-producing foods like beans, broccoli, onions, and lentils. Food intolerances are a major culprit — lactose intolerance is common, while fructose malabsorption is increasingly recognised. Keeping a detailed food diary for 2–4 weeks is the most effective way to identify personal triggers. The low-FODMAP diet, developed by Monash University, has strong evidence for reducing IBS-related bloating — work with a dietitian for best results. However, persistent bloating that doesn't fluctuate (always there, gradually worsening) should be investigated, as it can rarely be a sign of ovarian cancer — especially in women over 50.
When Stomach Pain Is Serious
Most stomach pain is benign, but certain patterns warrant urgent attention. Seek emergency care for: sudden, severe pain — especially if the abdomen is rigid and tender to touch (possible perforation or peritonitis); vomiting blood or 'coffee ground' vomit; passing black, tarry stools (melena — indicates upper GI bleeding); severe pain in the lower right abdomen with fever (possible appendicitis); and abdominal pain with inability to pass gas or stool (possible bowel obstruction). See your GP urgently for: persistent pain lasting more than 2 weeks; unexplained weight loss with abdominal symptoms; blood in stool (bright red or dark); difficulty swallowing (dysphagia); repeated vomiting; a feeling of a lump in your stomach; being diagnosed with iron deficiency anaemia; persistent change in bowel habits over 4+ weeks; and pain that wakes you from sleep. The key message: sudden severe pain = A&E. Persistent or worsening pain = GP within days.
- digestion
- stomach
- abdominal pain
Sources and further reading
This page was written from the following published guidance. All links checked 26 August 2026.