Stomach pain has dozens of possible causes, ranging from something as simple as eating too fast to conditions that need medical attention. Where the pain is, how it feels, and what else is happening in your body all point toward different explanations. Most episodes resolve on their own, but certain patterns signal something more serious.
Where the Pain Is Matters
Your abdomen holds a lot of organs packed into a relatively small space, and pain in different areas typically points to different sources. Upper right pain often involves the gallbladder or liver. Upper left pain can relate to the stomach, spleen, or pancreas. Lower right pain is most commonly associated with the appendix. Lower left pain often involves the large intestine, and in women, the reproductive organs on that side.
Pain right in the center of your abdomen, around or above the belly button, usually involves the stomach itself or the small intestine. Pain that starts in one spot and migrates to another is also a useful clue. Appendicitis, for instance, classically begins as a vague ache around the belly button and then shifts to the lower right side over several hours.
How the Pain Feels Tells You Something Too
Pain from internal organs like the stomach, intestines, and gallbladder tends to feel dull, diffuse, and hard to pinpoint. You might describe it as a deep ache or cramping that you can’t quite put your finger on. This type of pain can also show up in surprising places: gallbladder problems, for example, often cause pain between the shoulder blades or in the right shoulder, not just under the ribs.
Pain from the abdominal wall or the lining around your organs feels sharper and easier to locate. You can usually point to it with one finger. It gets worse when you move, cough, or press on the area. If vague, crampy pain suddenly becomes sharp and localized, that shift can mean an organ that was irritated has now become inflamed or perforated, which is a reason to get evaluated quickly.
One important difference: your body adapts to repeated skin-level pain (like pressing on a bruise), but internal organ pain doesn’t fade with repeated stimulus. That’s why stomach cramps can feel relentless in a way that a sore muscle doesn’t.
The Most Common Everyday Causes
For most people searching this question, the pain is probably coming from one of a handful of common and generally manageable sources.
Indigestion (functional dyspepsia): This is upper abdominal pain or discomfort that happens without any visible damage to the stomach. You might feel uncomfortably full after eating, get full much sooner than expected, or have a burning sensation in your upper abdomen. If these symptoms happen at least once a week and have been going on for three months or more, it qualifies as a chronic condition rather than a one-off episode. It’s caused by a communication problem between the gut and brain, not by an ulcer or other structural issue.
Gastritis and acid irritation: Inflammation of the stomach lining can cause a gnawing or burning pain in the upper abdomen, often worse on an empty stomach or after eating acidic or spicy foods. Over-the-counter pain relievers like ibuprofen and aspirin are the single most common drug cause of stomach lining damage. They work by suppressing a protective chemical in the stomach wall, leaving it vulnerable to acid. If you take these regularly and your stomach hurts, that connection is worth paying attention to.
Gas and bloating: Trapped gas can cause surprisingly intense, crampy pain that shifts around the abdomen. It often comes with visible bloating and relief after passing gas or having a bowel movement.
Constipation: When stool backs up, it can cause cramping and fullness, particularly in the lower left abdomen. Opioid pain medications and drugs with anticholinergic effects (many antidepressants and allergy medications fall into this category) are frequent culprits for drug-induced constipation.
Irritable Bowel Syndrome
IBS is one of the most common causes of recurring stomach pain, particularly if the pain comes with changes in bowel habits like alternating diarrhea and constipation. It’s classified as a disorder of gut-brain interaction, meaning the nerves in your digestive tract are essentially miscommunicating with your brain.
Two things happen in IBS. First, the muscles of the large intestine tend to contract more forcefully than normal, which directly causes cramping and pain. Second, the nerves in the gut become hypersensitive, so normal amounts of gas or stool movement that wouldn’t bother most people register as painful. People with IBS genuinely have a lower pain threshold in their digestive tract. It’s not imagined or exaggerated; the wiring is different. Stress, certain foods, hormonal changes, and disrupted sleep are common triggers.
Ulcers and H. Pylori
Peptic ulcers are open sores in the lining of the stomach or the first part of the small intestine. The two main causes are a bacterial infection called H. pylori and regular use of NSAIDs like ibuprofen, naproxen, or aspirin.
H. pylori is a surprisingly common bacterium that survives in stomach acid by producing an enzyme that neutralizes acid in its immediate surroundings. It triggers inflammation in the stomach lining, which in some people progresses to an ulcer. The tricky part is that most people carrying H. pylori never develop symptoms at all. When ulcers do form, they typically cause a burning or gnawing pain in the upper abdomen, often between meals or at night when the stomach is empty. The type of symptoms alone can’t reliably distinguish an ulcer from simple indigestion, which is why testing is usually needed.
Gallstones
Gallstone pain has a distinctive pattern. It comes on suddenly, intensifies rapidly, and settles in the upper right abdomen or just below the breastbone. It can radiate to the back between your shoulder blades or into your right shoulder. Episodes typically last several minutes to a few hours, then resolve. Pain often strikes after a fatty meal, since fat triggers the gallbladder to contract and squeeze against stones blocking its outlet.
Many people have gallstones and never know it. Pain only happens when a stone temporarily blocks a duct, so you can go long stretches between episodes.
Appendicitis
About 5% of people in the U.S. will develop appendicitis in their lifetime, and it’s most common between ages 10 and 30. The classic progression starts with vague pain around the belly button, followed by nausea and loss of appetite, then the pain shifts to the lower right abdomen and becomes more constant and intense over 12 to 24 hours. Up to 40% of people also develop a fever.
Only about half of appendicitis cases follow this textbook pattern, though. Kids, older adults, and pregnant people are especially likely to have atypical presentations. Some people get diarrhea, others get constipated. Some feel an urgent need to urinate. If you have worsening lower right abdominal pain that doesn’t let up, it needs evaluation regardless of whether you have every classic symptom.
Medications That Cause Stomach Pain
If your stomach started hurting around the time you began a new medication, the drug itself may be the cause. NSAIDs are the biggest offender, but they’re far from the only one. Antibiotics frequently cause abdominal pain and can disrupt the normal bacteria in the colon, sometimes leading to colitis. Certain antibiotics, particularly cephalosporins, are linked to a specific and potentially serious colon infection caused by the bacterium C. difficile.
Metformin, commonly prescribed for type 2 diabetes, causes diarrhea and stomach discomfort in a significant number of users. The antibiotic erythromycin causes pain by acting on receptors that speed up gut contractions. Even potassium supplements can directly injure the lining of the esophagus and stomach. Antidepressants with anticholinergic effects can relax the valve between the esophagus and stomach, causing acid reflux and heartburn.
When Stomach Pain Is an Emergency
Most stomach pain isn’t dangerous, but certain patterns require immediate medical care. The American College of Emergency Physicians advises seeking emergency care if pain is sudden, severe, or doesn’t ease within 30 minutes. Continuous severe pain accompanied by nonstop vomiting can indicate a serious or life-threatening condition.
Specific warning signs to watch for:
- Sudden, severe pain can indicate a perforated ulcer or ruptured blood vessel in the abdomen.
- Pain with fever and a rigid, tender abdomen suggests infection or inflammation spreading to the abdominal lining.
- Upper abdominal pain lasting days, worsening after eating, with nausea and rapid pulse fits the pattern of acute pancreatitis.
- Severe abdominal pain with vaginal bleeding in someone who could be pregnant may indicate an ectopic pregnancy.
- Worsening lower right pain with nausea and fever suggests appendicitis, which can progress to a rupture if untreated.
Pain that wakes you from sleep, pain accompanied by bloody or black stools, and pain with an inability to keep any fluids down are also reasons not to wait it out.