Dozens of things can make your stomach hurt, ranging from something as simple as eating too fast to serious conditions like appendicitis. Abdominal pain is one of the most common reasons people visit an emergency room, accounting for roughly 10% of all non-injury ER visits in the United States. Most of the time, the cause is temporary and manageable, but where the pain is, how long it lasts, and what other symptoms come with it can tell you a lot about what’s going on.
Food and Drink Triggers
The most common reason your stomach hurts on any given day is something you ate or drank. Indigestion, gas, constipation, and food intolerances are everyday culprits. If you’re lactose intolerant, for instance, dairy products trigger pain because undigested sugars ferment in your gut, producing gas and drawing extra water into your intestines. The same basic process happens with fructose and a group of carbohydrates known as FODMAPs, found in foods like onions, garlic, wheat, beans, and certain fruits.
Research in gastrointestinal physiology has shown that high-FODMAP foods can actually damage the intestinal barrier, allowing bacterial compounds to leak through and activate immune cells in the gut lining. This increases sensitivity to pain in the intestines, which is why some people feel sharp cramps after eating foods that don’t bother others at all. Food poisoning from contaminated meat, eggs, or produce is another obvious trigger. Salmonella, commonly picked up from undercooked poultry or eggs, causes fever, cramps, and often bloody diarrhea. Norovirus, the classic “stomach bug,” has a 24 to 48 hour incubation period and causes watery diarrhea and vomiting that typically resolves within a few days.
Medications That Irritate Your Stomach
Over-the-counter pain relievers like ibuprofen and naproxen are among the most common medications that cause stomach pain. These drugs weaken the protective mucus layer that shields your stomach lining from its own acid. Used occasionally, they’re usually fine. But regular use can lead to inflammation of the stomach lining (gastritis), ulcers, and in rare cases, bleeding or perforation. Antibiotics are another frequent offender, as they disrupt the balance of bacteria in your gut and commonly cause cramping and diarrhea during a course of treatment.
Chronic Digestive Conditions
When stomach pain keeps coming back over weeks or months, a handful of conditions are usually responsible.
Gastritis and acid reflux (GERD) both involve stomach acid irritating tissue that isn’t designed to handle it. Gastritis inflames the stomach lining itself, while GERD sends acid upward into the esophagus, causing burning pain in the upper abdomen and chest. Both tend to flare after meals, with spicy or fatty foods, alcohol, and caffeine making things worse.
Irritable bowel syndrome (IBS) affects the intestines and causes cramping, bloating, diarrhea, constipation, or an alternating mix of both. It’s considered a “functional” disorder, meaning the gut looks normal on imaging but doesn’t behave normally. Diagnosis typically requires recurring symptoms involving abdominal pain linked to bowel movements, along with changes in stool frequency or appearance, with no structural explanation found on testing.
Peptic ulcers are open sores on the stomach lining or the upper part of the small intestine, most commonly caused by a bacterial infection or long-term use of anti-inflammatory painkillers. The pain is often a burning or gnawing sensation between meals that temporarily improves after eating.
Gallstones can block the bile duct and cause intense pain in the upper right abdomen, often after a fatty meal. The pain typically comes in waves and may radiate to the right shoulder or back.
Where the Pain Is Matters
The location of your pain is one of the most useful clues for narrowing down the cause. Pain in the upper right side of your abdomen points toward gallbladder problems, particularly cholecystitis (an inflamed gallbladder). Pain in the lower right side is the classic location for appendicitis. Lower left pain in adults is most commonly associated with diverticulitis, where small pouches in the colon wall become inflamed or infected. Upper left pain can signal pancreatitis, an enlarged spleen, or a stomach ulcer.
Pain that’s hard to pinpoint, spreading across the whole abdomen, is more typical of gas, a stomach virus, IBS, or constipation. Central pain around the belly button that migrates to the lower right over several hours is a hallmark pattern of appendicitis.
Causes Outside the Digestive Tract
Not all stomach pain starts in the stomach. Kidney stones produce severe pain that usually begins in the back or side and radiates toward the lower abdomen and groin. Urinary tract infections can cause lower abdominal pain along with burning during urination. In women, ovarian cysts, endometriosis, and pelvic inflammatory disease are common causes of lower abdominal pain that have nothing to do with digestion.
More surprisingly, pneumonia in the lower lobes of the lungs can refer pain to the upper abdomen. Even heart attacks can present as upper abdominal discomfort rather than the expected chest pain, particularly in women and older adults. A pulled or strained abdominal muscle from exercise or heavy lifting can also mimic internal pain, though it typically worsens with specific movements and feels tender to the touch.
Stress and Your Gut
Your brain and gut share a direct nerve connection, which is why anxiety, stress, and emotional distress can produce very real stomach pain. Stress increases acid production, speeds up or slows down digestion, and heightens the sensitivity of nerve endings in the intestines. People with IBS often notice that their symptoms flare during periods of high stress, not because the condition is imaginary, but because the nervous system amplifies signals from the gut when it’s already on high alert.
Pain That Needs Immediate Attention
Most stomach pain resolves on its own or with simple treatment. But certain patterns signal something that can’t wait. Pain so severe it prevents you from standing or functioning normally, pain accompanied by vomiting that won’t stop or an inability to keep liquids down, and pain with a high fever or rapid pulse all warrant urgent evaluation.
Appendicitis specifically tends to start as mild pain near the belly button, then move to the lower right abdomen and intensify over a matter of hours. It gets worse with movement, coughing, or sneezing, and often comes with loss of appetite, nausea, fever, and an inability to pass gas. If you’ve had previous abdominal surgery, new pain in the same area could indicate adhesions or bowel obstruction, both of which need prompt assessment. Pain that resembles something you’ve experienced before but feels significantly worse or different this time is also worth taking seriously.
Narrowing Down Your Own Symptoms
When you’re trying to figure out what’s causing your stomach pain, a few questions help sort the common from the concerning. Think about timing: did it start suddenly or build gradually? Pain after eating suggests acid reflux, gastritis, gallstones, or food intolerance. Pain unrelated to meals could point toward kidney stones, a UTI, or a muscle strain. Consider what makes it better or worse. Antacids helping suggests acid-related causes. Pain that worsens when you press on a specific spot may indicate localized inflammation.
Track how long it lasts. A few hours of cramping after a questionable meal is likely food poisoning or gas. Pain persisting beyond a few days, recurring weekly, or waking you up at night points toward something that needs a proper workup. Associated symptoms matter too: blood in your stool, unexplained weight loss, persistent vomiting, or yellowing of the skin all change the picture significantly and suggest conditions that benefit from early diagnosis.