Stomach pain has dozens of possible causes, ranging from something as simple as gas or a meal that didn’t agree with you to conditions that need prompt medical attention. The location of your pain, when it started, and what makes it better or worse are the most useful clues for narrowing down what’s going on.
Where the Pain Is Matters
Your abdomen contains many organs packed closely together, and each one produces pain in a slightly different spot. Pain in the upper middle area, just below your breastbone, often points to the stomach itself, whether from acid irritation, an ulcer, or simple indigestion. Pain in the upper right side that comes on suddenly and intensifies quickly is a hallmark of gallstones, and it can radiate to your back between the shoulder blades or into your right shoulder. That type of pain typically lasts anywhere from several minutes to a few hours.
Lower abdominal pain has its own set of causes. Pain that starts around your belly button and then migrates to the lower right side is the most telling sign of appendicitis. That migration pattern is correct about 80% of the time when appendicitis is actually present. Pain lower down on either side, especially in women, can involve the ovaries, fallopian tubes, or bladder.
Common Everyday Causes
Most stomach pain is temporary and tied to digestion. Eating too fast, swallowing air, fatty or spicy foods, and stress can all trigger discomfort that resolves on its own. Gas and bloating are the most frequent culprits, and they tend to cause crampy, shifting pain that improves after passing gas or having a bowel movement.
Food intolerances are another common source. About 1% of the U.S. population has celiac disease, where gluten triggers an autoimmune response that damages the small intestine. Another 6% may have a non-celiac gluten sensitivity that causes bloating, gas, and abdominal distension even without the intestinal damage. Symptoms from gluten can appear hours to days after eating it, which makes it harder to connect the dots. Lactose intolerance works differently: it causes cramping and bloating within a couple of hours of consuming dairy, because undigested lactose ferments in the gut.
Acid-Related Problems
A burning or aching pain in the upper stomach area that gets worse on an empty stomach often signals gastritis (inflammation of the stomach lining) or a peptic ulcer. One of the most common drivers is a bacterial infection called H. pylori. This bacterium damages the protective mucus layer of the stomach, allowing acid to eat into the tissue and create open sores. Many people carry H. pylori without symptoms, but when problems develop, the pain is typically a gnawing or burning sensation that may improve briefly after eating, then return.
Over-the-counter pain relievers like ibuprofen and aspirin are another major cause of stomach lining damage. These drugs weaken the stomach’s protective barrier by disrupting the fatty layer that keeps acid from reaching the tissue underneath. They also reduce blood flow to the stomach wall, making it harder for the lining to repair itself. Taking these medications regularly, especially on an empty stomach, significantly raises the risk of erosions and ulcers.
When Pain Keeps Coming Back
If your stomach hurts frequently but tests and scans come back normal, you may have what’s called functional dyspepsia. This is diagnosed when someone has persistent upper stomach pain, burning, uncomfortable fullness after meals, or an inability to finish a normal-sized meal, and no structural cause can be found. It’s not “all in your head.” The current understanding is that the nerves in the gut are overly sensitive, or the stomach doesn’t relax and empty the way it should.
Irritable bowel syndrome (IBS) is a related condition, but the pain tends to sit lower in the abdomen and is closely linked to bowel habits. The diagnostic pattern is abdominal pain at least one day per week that’s connected to changes in how often you go, how your stool looks, or whether the pain improves after a bowel movement. Many people with IBS cycle between constipation and diarrhea, and stress reliably makes symptoms worse.
Pain That Needs Urgent Attention
Certain patterns of stomach pain signal something potentially dangerous. The American College of Emergency Physicians recommends seeking emergency care if pain is sudden, severe, or doesn’t ease within 30 minutes. Continuous severe pain paired with nonstop vomiting is another red flag.
Appendicitis typically starts with vague pain around the belly button, then shifts to the lower right abdomen over 12 to 24 hours. Loss of appetite, nausea, and sometimes fever follow. One useful detail: with appendicitis, pain almost always comes before vomiting. If vomiting comes first, that pattern is more consistent with a bowel obstruction.
Pancreatitis produces pain in the middle upper abdomen that can be severe, constant, and worsened by eating. It often comes with nausea, a swollen tender belly, fever, and a rapid pulse. Heavy alcohol use and gallstones are the two most common triggers.
For women of childbearing age, an ectopic pregnancy is a critical consideration. Early signs include pelvic pain and light vaginal bleeding, sometimes alongside the usual early pregnancy symptoms like a missed period and nausea. A pregnancy test will still be positive. If the ectopic pregnancy ruptures, it can cause extreme lightheadedness, fainting, shoulder pain (from internal bleeding irritating the diaphragm), and shock. This is a surgical emergency.
Clues That Help You Sort It Out
Paying attention to a few details can help you and your doctor figure out the cause faster. Consider the timing: does the pain hit right after eating, an hour later, or on an empty stomach? Acid-related pain often worsens between meals and at night. Gallstone pain tends to strike after fatty meals. IBS pain frequently improves after a bowel movement.
Think about what else is happening alongside the pain. Fever suggests infection or inflammation. Bloating and gas point toward food intolerance or functional gut issues. Unintentional weight loss, blood in your stool, or vomiting blood are signs that something more serious is going on and shouldn’t be waited out. Pain that wakes you from sleep is also more likely to have a structural cause than pain that only bothers you during the day.
For pain that’s mild, came on gradually, and doesn’t have any of the warning signs above, it’s reasonable to monitor it for a day or two. Avoiding irritants like alcohol, coffee, spicy food, and NSAIDs gives your stomach lining a chance to calm down. But pain that persists beyond a few days, keeps returning in a pattern, or gradually worsens deserves a proper evaluation.