Stomach pain has dozens of possible causes, ranging from something as simple as gas or a pulled muscle to serious conditions like appendicitis or gallbladder disease. The location of your pain, how long it lasts, and what other symptoms come with it are the most useful clues for narrowing down what’s going on. Most episodes of abdominal pain resolve on their own within hours, but certain patterns signal something that needs medical attention fast.
Where the Pain Is Matters
Your abdomen is divided into four general zones, each housing different organs. Pain in your upper right side typically points to your liver, gallbladder, or the first section of your small intestine. Upper left pain is more often linked to your stomach or spleen. Lower right pain is the classic territory for your appendix. And lower left pain commonly involves your large intestine, particularly the sigmoid colon, where problems like diverticulitis tend to show up.
These aren’t hard rules. Pain can radiate, shift, or start in one area and settle in another. Appendicitis, for example, often begins as a vague ache around the belly button before migrating to the lower right side over several hours. Gallbladder pain can send a sharp sensation up to your right shoulder blade. But if you can point to a specific spot that hurts the most, that gives you and your doctor a head start.
Gas, Bloating, and Indigestion
The most common causes of stomach pain aren’t dangerous. Trapped gas can create surprisingly intense cramping that moves around the abdomen and then disappears once you pass it. Eating too quickly, swallowing air, or consuming foods that ferment in the gut (beans, cruciferous vegetables, dairy if you’re lactose intolerant) all contribute. Indigestion from overeating, spicy food, or alcohol causes a burning or gnawing sensation in the upper abdomen that usually fades within a few hours.
Constipation is another overlooked cause. When stool builds up in the colon, it creates pressure and cramping, often in the lower left abdomen. This can become genuinely painful if it persists for several days.
Food Poisoning and Stomach Bugs
If your stomach pain comes with nausea, vomiting, or diarrhea, an infection is a likely culprit. The timing helps distinguish food poisoning from a stomach virus. Food poisoning typically hits fast, within two to six hours of eating contaminated food, and tends to burn through your system relatively quickly. A stomach virus (viral gastroenteritis) has a longer incubation period of 24 to 48 hours, and symptoms generally linger for about two days, sometimes longer.
Both cause cramping abdominal pain, but food poisoning is more likely to come on suddenly after a specific meal, while a stomach bug often spreads through contact with an infected person. Either way, dehydration is the main risk, especially in children and older adults.
Peptic Ulcers
A peptic ulcer is an open sore in the lining of your stomach or the upper part of your small intestine. The hallmark symptom is a burning pain in the upper abdomen that often worsens on an empty stomach and temporarily improves after eating. The pain can wake you up at night.
The causes have shifted over the decades. Long-term use of anti-inflammatory painkillers like ibuprofen and aspirin now accounts for the majority of ulcers. Only about one in five peptic ulcers is linked to a bacterial infection called H. pylori, according to a cross-sectional study of more than one million patients who underwent upper endoscopy. That’s a reversal from earlier assumptions, and it means frequent use of over-the-counter pain relievers is a bigger risk factor than most people realize.
Gallbladder Problems
Gallbladder pain typically strikes in the upper right abdomen, often after a fatty meal. When a gallstone temporarily blocks the duct leading out of the gallbladder, the result is biliary colic: a sudden, intense pain that may radiate to the shoulder, accompanied by sweating and vomiting. This pain is steady (not truly “colicky” despite the name) and usually lasts up to three hours before resolving.
If the pain persists beyond three hours, that’s the dividing line for a more serious problem. Prolonged obstruction can lead to acute cholecystitis, where the gallbladder becomes inflamed or infected. The pain may start in the middle of the upper abdomen and then shift to the right side, and you may develop a fever. This requires prompt medical evaluation.
Appendicitis
Appendicitis is one of the most common surgical emergencies involving abdominal pain. It follows a fairly distinctive pattern: pain starts around the belly button, then over the course of several hours migrates to the lower right abdomen, where it becomes sharp and localized. You may also lose your appetite, feel nauseated, or develop a low-grade fever.
A useful self-check is whether coughing, hopping, or pressing on the lower right side makes the pain significantly worse. Rebound tenderness, where the pain spikes when you release pressure rather than when you press down, is another warning sign. If the appendix ruptures, the pain can suddenly become severe and widespread, with a rigid abdomen and signs of serious illness. Suspected appendicitis warrants an emergency room visit, not a wait-and-see approach.
Diverticulitis
Diverticulitis occurs when small pouches that form in the wall of the colon become inflamed or infected. It’s most common in people over 40 and is strongly associated with a low-fiber diet. The pain is typically in the lower left abdomen, and it tends to be constant rather than coming and going. Fever, changes in bowel habits (sudden diarrhea or constipation), and tenderness when the area is touched are common accompanying symptoms.
Mild cases can sometimes be managed at home, but constant, unexplained pain in the lower left side with a fever needs medical attention, as complications like perforation or abscess formation can develop.
Irritable Bowel Syndrome and Inflammatory Bowel Disease
Chronic or recurring stomach pain that lasts weeks or months points toward different possibilities than a one-time episode. Irritable bowel syndrome (IBS) causes cramping, bloating, and altered bowel habits (diarrhea, constipation, or both) without visible damage to the intestines. The pain often improves after a bowel movement and tends to flare during periods of stress or after eating certain foods.
Inflammatory bowel disease is a different category. Ulcerative colitis affects only the colon, starting at the rectum and extending upward in a continuous stretch. It typically causes cramps and bleeding centered in the lower abdomen. Crohn’s disease can affect any part of the digestive tract from mouth to anus, often in patchy, disconnected segments. It tends to cause belly pain with diarrhea (often without blood) and unintended weight loss, especially when the small intestine is involved. Both conditions require diagnosis through imaging or endoscopy and long-term management.
Causes That Aren’t in Your Gut
Some causes of abdominal pain originate outside the digestive system entirely. Kidney stones produce a sudden, gripping pain that starts in the back just below the ribs and can radiate around to the abdomen or groin. The pain comes in waves and is often described as one of the most intense pains a person can experience.
Heart attacks can also cause upper abdominal pain, sometimes mistaken for heartburn or indigestion, particularly in women. If upper stomach pain comes with chest pressure, pain radiating to the jaw, arms, neck, or back, shortness of breath, or cold sweats, treat it as a cardiac emergency.
In women, ovarian cysts, ovarian torsion, ectopic pregnancy, and pelvic inflammatory disease can all present as lower abdominal pain. Urinary tract infections sometimes cause lower abdominal discomfort along with burning during urination and frequent urges to go. Pulled abdominal muscles from exercise or heavy lifting can mimic internal pain but typically worsen with movement and feel tender to the touch on the surface.
Signs You Need Emergency Care
Most stomach pain doesn’t require a trip to the emergency room. But certain combinations of symptoms change that calculation. Seek immediate care if your pain is so severe it prevents you from functioning normally, if you’re vomiting and unable to keep any liquids down, if you have a rigid or distended abdomen, or if there’s blood in your vomit or stool.
Pain that’s similar to something you’ve experienced before but notably more severe or different in character also warrants urgent evaluation. If you’ve had previous abdominal surgery, new abdominal pain could signal adhesions or bowel obstruction, and it should be assessed promptly. Complete inability to have a bowel movement combined with severe pain is another red flag, as it can indicate a blockage.