Stomach pain is one of the most common reasons people seek medical care, accounting for over 6.4 million emergency department visits in the United States in 2018 alone. Most of the time, the cause is something temporary and manageable like indigestion or a stomach bug. But where the pain is, how it feels, and how long it lasts all offer clues about what’s going on inside your body.
Where the Pain Is Matters
Your abdomen holds dozens of organs packed into a relatively small space, and pain in different areas points to different problems. Upper abdominal pain, especially in the center just below your ribs, is most commonly tied to your stomach and the first part of your small intestine. Burning or gnawing pain after eating often comes from acid reflux, gastritis (inflammation of the stomach lining), or an ulcer. Ulcers feel like a deep, penetrating burn that can wake you up at night or flare between meals.
Pain in the upper right side may involve your gallbladder or liver. Gallstones are a frequent culprit, especially after fatty meals, producing intense pain that can radiate to your right shoulder blade. Upper left pain is less common but can involve the spleen or pancreas. Pancreatic pain tends to be severe and radiates straight through to your back.
Lower abdominal pain opens up a wider range of possibilities: appendicitis, diverticulitis, urinary tract infections, kidney stones, hernias, and bowel problems. Appendicitis has a distinctive pattern where pain starts around the belly button and moves to the lower right side over several hours. Diverticulitis, more common in people over 40, typically shows up as lower left pain with fever and changes in bowel habits.
What the Pain Feels Like
The character of your pain tells you something about its source. Your internal organs have far fewer pain-sensing nerves than your skin and muscles, and those nerves are spread out. That’s why organ pain (called visceral pain) tends to feel dull, achy, crampy, or like deep pressure rather than a sharp, pinpoint sensation. It can be hard to describe or point to exactly. People often use words like “squeezing,” “gnawing,” or just “a heavy feeling.”
Sharp, well-localized pain is more typical when inflammation has spread to the lining of your abdominal wall. This is why appendicitis starts as a vague ache near your belly button (the inflamed appendix irritating internal nerves) and later becomes a sharp, specific pain in the lower right (when inflammation reaches the abdominal wall, where nerve endings are more concentrated).
Cramping that comes and goes in waves usually signals your intestines or other hollow organs squeezing hard, whether from a stomach bug, gas, food intolerance, or a blockage. Constant, unrelenting pain is generally more concerning than pain that fades in and out.
The Most Common Causes
When researchers look at what actually sends people to the emergency room for abdominal pain, the two most frequent diagnoses are gastroenteritis (a stomach bug) and nonspecific abdominal pain, meaning no serious cause is found. Together these account for about 21% of cases. Gallstones, kidney stones, diverticulitis, and appendicitis each make up roughly 4% of cases.
Outside of emergencies, the everyday causes of stomach pain are even more mundane. Gas and bloating, constipation, food intolerances, overeating, stress, and mild food poisoning cause the vast majority of stomachaches people experience at home. Menstrual cramps are another extremely common source of lower abdominal pain that doesn’t involve the digestive system at all.
Irritable Bowel Syndrome
If your stomach pain keeps coming back alongside changes in your bowel habits, IBS is a likely explanation. IBS produces repeated abdominal pain with diarrhea, constipation, or an unpredictable mix of both. There’s no visible damage to your digestive tract; the problem is in how your gut functions and communicates with your brain. Some people lean toward constipation (hard, lumpy stools on most bad days), others toward diarrhea (loose, watery stools), and many swing between the two. Pain often improves after a bowel movement and worsens with stress or certain foods.
Causes Specific to Women
Several conditions unique to female reproductive anatomy can produce pain that feels like a stomachache but originates in the pelvis. Ovarian cysts can rupture or bleed, causing sudden, sharp one-sided pain. Endometriosis, where tissue similar to the uterine lining grows outside the uterus, can cause chronic pelvic pain that worsens around periods and sometimes leads to intestinal symptoms that mimic IBS.
Pelvic inflammatory disease, usually from an untreated sexually transmitted infection, produces lower abdominal pain with fever and sometimes abnormal discharge. An ectopic pregnancy, where a fertilized egg implants outside the uterus (most often in a fallopian tube), causes lower abdominal pain that can become a medical emergency if the tube ruptures. Fibroids in the uterus can also cause pain, particularly when they outgrow their blood supply or twist on a stalk.
Pain That Isn’t Coming From Your Gut
Some causes of stomach pain have nothing to do with digestion. Kidney stones produce intense flank pain that radiates into the lower abdomen and groin. Urinary tract infections can cause lower abdominal pressure and pain along with burning urination. Pulled abdominal muscles from exercise or coughing can mimic internal pain.
More seriously, a heart attack can present as upper abdominal or chest pain, especially in women and older adults who may not feel the classic chest-clutching sensation. If your upper abdominal pain comes with shortness of breath, pain in your neck, shoulder, or between your shoulder blades, or nausea without an obvious stomach cause, that combination needs immediate attention.
Acute Pain vs. Pain That Keeps Returning
Pain lasting less than seven days is considered acute. The most common acute causes, like food poisoning and viral gastroenteritis, resolve on their own within a few days. More serious acute causes like appendicitis and gallbladder inflammation typically escalate quickly, with worsening pain, fever, and vomiting pushing you toward medical care within hours.
Chronic or recurring abdominal pain, lasting weeks to months, points toward conditions like IBS, acid reflux, ulcers, food intolerances, endometriosis, or inflammatory bowel disease. These conditions tend to have patterns: pain tied to eating, to bowel movements, to menstrual cycles, or to stress. Tracking when your pain happens and what makes it better or worse gives your doctor the most useful information for narrowing down the cause.
How Stomach Pain Gets Diagnosed
Your doctor’s first and most powerful tool is your description of the pain: where it is, how it feels, when it started, what makes it worse, and what other symptoms come with it. From there, the workup depends on what they suspect.
Blood tests can check for infection, anemia, inflammation, and problems with your liver, kidneys, or pancreas. Stool samples can reveal hidden blood, infection, or signs of food intolerance. An abdominal CT scan creates detailed images that help identify appendicitis, kidney stones, diverticulitis, and other structural problems. Ultrasound is often the first imaging choice for gallbladder issues and, in women, for ovarian and uterine problems.
For ongoing pain, your doctor may recommend looking directly inside your digestive tract. An upper endoscopy uses a thin flexible camera passed through your mouth to examine your esophagus, stomach, and upper small intestine for ulcers, inflammation, or infection. A colonoscopy examines the full length of your colon. For harder-to-reach areas of the small intestine, a capsule endoscopy lets you swallow a pill-sized camera that transmits images as it travels through.
Signs You Need Emergency Care
Most stomachaches don’t require a trip to the ER, but certain features signal something potentially dangerous. Sudden, severe pain that hits like a switch being flipped raises concern for a ruptured organ, a twisted bowel, a burst blood vessel, or a perforated ulcer. Pain that is severe and keeps getting worse over hours, rather than coming in waves, is another red flag.
Vomiting blood or material that looks like coffee grounds suggests bleeding in your stomach or esophagus. Bloody stool combined with significant abdominal pain can indicate compromised blood flow to the intestines. A rigid abdomen that feels board-like and is extremely tender to touch suggests inflammation has spread to the abdominal lining.
Abnormal vital signs tell their own story. A racing heart, rapid breathing, lightheadedness, or fainting alongside abdominal pain can indicate internal bleeding or sepsis. In women of childbearing age, severe one-sided lower abdominal pain with lightheadedness warrants ruling out a ruptured ectopic pregnancy, which can cause life-threatening internal bleeding.