Stomach pain has dozens of possible causes, ranging from something you ate an hour ago to a condition that needs medical attention. The location, timing, and type of pain all point toward different explanations. Most episodes are temporary and tied to digestion, stress, or minor irritation, but certain patterns signal something more serious.
Where the Pain Is Matters
Your abdomen contains many organs packed into a relatively small space, and pain in different areas points to different sources. What most people call “stomach pain” could actually originate from your intestines, gallbladder, pancreas, or reproductive organs.
Pain in the upper middle area (just below your ribs) most often involves the stomach itself, the pancreas, or the first section of the small intestine. This is where you’ll feel acid reflux, ulcers, and gastritis. Upper right pain tends to involve the gallbladder or liver. Upper left pain can come from the spleen or the tail of the pancreas.
Lower right pain is the classic location for appendicitis, though it can also stem from the colon or, in women, the right ovary. Lower left pain often involves the lower colon. Pain that’s hard to pinpoint or seems to radiate across your whole belly is more typical of gas, bloating, or generalized intestinal cramping.
The Most Common Culprits
For most people searching this question, the answer falls into one of a few categories: acid-related irritation, food intolerance, muscle cramping in the intestines, or stress.
Acid reflux (GERD) affects roughly 20% of the population. It happens when the muscular valve between your esophagus and stomach relaxes too easily, letting acid splash upward. The result is a burning sensation in your upper abdomen or chest, often worse after meals or when lying down. Being overweight, smoking, and certain medications (including some blood pressure drugs, painkillers, and antidepressants) all increase the risk.
Peptic ulcers cause a similar burning pain in the upper abdomen, but the mechanism is different. Instead of acid going the wrong direction, the protective lining of your stomach or small intestine gets damaged, exposing the tissue underneath to acid. The two main causes are a bacterial infection called H. pylori and long-term use of anti-inflammatory painkillers like ibuprofen, aspirin, or naproxen. These drugs suppress the protective compounds your stomach lining depends on, creating a “dual insult” that leads to erosion and, sometimes, bleeding.
Foods That Trigger Pain and Bloating
Certain carbohydrates are poorly absorbed in the small intestine. When they reach the large intestine undigested, gut bacteria ferment them, producing gas that stretches the intestinal walls and causes cramping, bloating, diarrhea, or constipation. The most common triggers include dairy products, wheat-based foods, beans and lentils, and certain fruits and vegetables like apples, pears, cherries, onions, garlic, and asparagus.
If your pain reliably shows up after eating and eases after a bowel movement, food intolerance is a likely explanation. An elimination approach, where you remove suspected triggers for a few weeks and reintroduce them one at a time, can help you identify which foods are causing problems. This strategy is the basis of the low-FODMAP diet, which Johns Hopkins Medicine recommends for people with irritable bowel syndrome or bacterial overgrowth in the small intestine.
Why Stress Makes Your Stomach Hurt
The connection between anxiety and stomach pain is not imaginary. Your gut and brain communicate constantly through shared hormones and nerve pathways. When you’re stressed, your body releases hormones that increase intestinal permeability (essentially making your gut lining “leakier”) and alter how your intestines move and contract. Stress also changes the activity of specialized cells in your gut lining that produce serotonin, a chemical involved in both mood regulation and pain signaling. This is why both chronic stress and early-life stress are strongly linked to functional digestive disorders.
The practical result: stress can make your gut more sensitive to normal sensations like stretching or movement, turning what should feel like nothing into genuine pain. This heightened sensitivity, called visceral hypersensitivity, is a core feature of conditions like IBS.
IBS vs. Inflammatory Bowel Disease
IBS is one of the most common reasons for chronic stomach pain. It’s diagnosed when you’ve had abdominal pain for at least 12 weeks out of the past year, along with changes in how often you go to the bathroom or what your stool looks like. Symptoms tend to flare after large meals or during stressful periods and often improve temporarily after a bowel movement. IBS does not cause inflammation or permanent damage to the intestines.
Inflammatory bowel disease (Crohn’s disease and ulcerative colitis) is a different situation entirely. IBD causes destructive inflammation that can permanently harm the intestinal lining. Key differences from IBS include bleeding, anemia, unexplained weight loss, and fever. If you’re experiencing any of those alongside chronic abdominal pain, that distinction matters for getting the right diagnosis.
Pain That Moves: The Appendicitis Pattern
Appendicitis has a distinctive pain pattern worth knowing. It typically starts as mild, vague discomfort near the belly button, easily mistaken for a regular stomachache. Over the next 12 to 24 hours, the pain sharpens and migrates to the lower right abdomen as inflammation worsens. Other symptoms include loss of appetite, nausea or vomiting, fever, and difficulty passing gas. If your pain follows this migration pattern and keeps getting worse rather than coming and going, that warrants an emergency room visit.
Painkillers That Cause Pain
It’s worth noting the irony: one of the most common causes of stomach pain is the medication people take for other pain. Ibuprofen, aspirin, and naproxen all interfere with your stomach’s ability to maintain its protective mucous barrier. Occasional use at normal doses is generally fine for most people, but regular or high-dose use can cause gastritis (inflammation of the stomach lining) or ulcers. If you rely on these medications frequently and notice a burning or gnawing pain in your upper abdomen, the pills themselves may be the problem.
Pelvic Pain That Feels Like Stomach Pain
In women, pain that seems to come from the lower abdomen can originate from the reproductive organs instead of the digestive tract. Ovarian cysts, endometriosis, and pelvic infections can all produce pain that overlaps with intestinal symptoms like bloating, constipation, or nausea. Clues that the source might be gynecological include pain that fluctuates with your menstrual cycle, changes in vaginal discharge, irregular periods, or pain during intercourse. Sharp, sudden pelvic pain accompanied by heavy vaginal bleeding, fever, or fainting requires emergency evaluation.
When Stomach Pain Is an Emergency
Most stomach pain resolves on its own or with simple changes. But certain features suggest something that needs immediate attention. Pain so severe it prevents you from functioning normally, pain paired with uncontrollable vomiting or an inability to keep liquids down, complete inability to have a bowel movement combined with worsening pain, and pain that started mild but has steadily worsened over hours are all reasons to seek urgent care.
Pancreatitis deserves specific mention: it produces upper abdominal pain that may start mild, worsens after eating, and can escalate to severe, constant pain with nausea, fever, and a rapid pulse. If your pain has a familiar quality from a past episode but feels different this time, more intense or accompanied by new symptoms, treat it as something new rather than assuming it’s the same old issue.