Diagnosing stomach pain starts with two things: where it hurts and what other symptoms come with it. Because so many organs are packed into the abdomen, pain in this area can stem from dozens of different conditions, and the location, timing, and character of the pain are often the most important clues. Doctors use a combination of your symptom history, a physical exam, blood or urine tests, and sometimes imaging to narrow down the cause.
Why Location Matters So Much
The abdomen is loosely divided into regions, and each region maps to different organs. Pain in the upper middle area (just below the breastbone) typically involves the stomach, esophagus, or pancreas and is linked to conditions like ulcers, acid reflux, gastritis, and pancreatitis. That same zone can also signal a heart attack, which is why doctors take upper abdominal pain seriously even when the gut seems like the obvious culprit.
Pain in the upper right side usually points to the gallbladder or liver. Gallstones, gallbladder inflammation, and hepatitis all concentrate there. Upper left pain is less common and typically involves the spleen. Lower abdominal pain opens up a wider list: appendicitis, diverticulitis, urinary tract infections, kidney stones, hernias, and in women, ovarian or fallopian tube problems like ovarian torsion or ectopic pregnancy.
One classic pattern doctors look for is appendicitis pain that starts vaguely around the belly button, then migrates over several hours to the lower right side. Diverticulitis tends to settle in the lower left. These migration patterns can be more telling than where the pain is at any single moment.
Pain doesn’t always come from the abdomen itself. Pneumonia in the lower right lung can produce pain that feels like it’s in the lower right belly, because the same nerves supply both the lung lining and the abdominal wall. Kidney and ureteral stones create severe flank pain that can radiate to the groin, testicle, or labia. Irritation of the diaphragm from an abdominal condition can even produce referred pain in the shoulder.
What Your Doctor Listens For
Before any test is ordered, the conversation you have with your doctor does most of the diagnostic work. Key questions include: when the pain started, whether it came on suddenly or gradually, whether it’s constant or comes in waves, and what makes it better or worse. Crampy, wave-like pain often points to something being squeezed or obstructed, like a kidney stone or intestinal blockage. Steady, worsening pain that gets worse with movement suggests inflammation, like appendicitis or peritonitis.
Associated symptoms narrow things further. Nausea and vomiting alongside the pain suggest involvement of the stomach, gallbladder, or a bowel obstruction. Fever and chills point toward infection. Changes in bowel habits, bloody or tarry stools, urinary frequency, or blood in the urine each redirect the investigation. Jaundice (yellowing of the skin or eyes) shifts attention to the liver or bile ducts.
The Physical Exam
Doctors use specific hands-on tests to check for particular conditions. For suspected appendicitis, they press on McBurney’s point, a spot about two inches inward from the right hip bone toward the belly button. This test picks up appendicitis about 83% of the time. They may also press on the left side of the abdomen to see if it triggers pain on the right (Rovsing’s sign), which has a specificity as high as 93% for appendicitis.
For gallbladder problems, doctors use Murphy’s sign: they press beneath the right rib cage and ask you to inhale deeply. If you stop mid-breath because of a sharp catch of pain, that’s a positive result. Sensitivity for this test ranges from 48% to 97% depending on the clinical scenario, which is why it’s used alongside other evidence rather than in isolation.
Doctors also listen to your abdomen with a stethoscope (absent bowel sounds can indicate a bowel obstruction or peritonitis), check for abdominal rigidity or guarding, and assess whether the pain worsens when they quickly release pressure, a sign of peritoneal irritation.
Blood and Urine Tests
Lab work helps confirm or rule out specific diagnoses. A complete blood count showing elevated white blood cells suggests infection or inflammation. Liver enzyme levels point toward hepatitis or bile duct problems. Elevated pancreatic enzyme levels (lipase) are the primary marker for pancreatitis. A pregnancy test is standard for women of reproductive age with lower abdominal pain, since ectopic pregnancy is both common and dangerous.
Urinalysis checks for blood in the urine (suggesting kidney stones) or signs of urinary tract infection. Inflammatory markers like C-reactive protein are frequently ordered in emergency settings, though they indicate general inflammation rather than a specific diagnosis. Lactate levels can flag dangerously reduced blood flow to the intestines or sepsis, both of which require urgent treatment.
Imaging: Ultrasound, CT, and Endoscopy
When the exam and labs aren’t enough, imaging fills in the picture. The two most common options are ultrasound and CT scan, and the choice depends on the suspected condition and the patient.
CT scans are the gold standard for acute abdominal pain in adults. For appendicitis specifically, CT has a sensitivity of 94% and specificity of 95%, meaning it catches nearly all true cases and rarely gives false alarms. Ultrasound is less accurate for appendicitis, with sensitivity around 86% and specificity around 81%, but it has a major advantage: no radiation. That makes it the preferred first step for children and pregnant women. For gallbladder disease, ultrasound is actually the better tool and is typically the first imaging ordered.
Scope-based procedures are used when the source of pain appears to be in the lining of the digestive tract itself. An upper endoscopy (a thin camera passed through the mouth) is used for persistent upper abdominal symptoms like heartburn, nausea, or difficulty swallowing, and can diagnose ulcers, inflammation, and upper GI conditions directly. A colonoscopy (camera through the rectum) is indicated when pain comes with persistent changes in bowel habits, rectal bleeding, or concerns about the colon and lower intestines.
Diagnosing Chronic Stomach Pain
Not all stomach pain is acute. If you’ve had recurring abdominal pain for months, the diagnostic approach shifts. One of the most common chronic diagnoses is irritable bowel syndrome (IBS), which is identified using the Rome IV criteria: recurrent abdominal pain at least one day per week for the past three months, linked to at least two of the following: the pain relates to bowel movements, there’s been a change in how often you go, or there’s been a change in stool consistency. Symptoms must have started at least six months before diagnosis. There’s no single test for IBS. It’s diagnosed by matching the symptom pattern and ruling out other causes.
Other chronic causes like celiac disease, inflammatory bowel disease, or food intolerances require targeted testing, including specific blood antibodies, stool samples, or biopsies taken during endoscopy. Chronic pain that wakes you at night, causes unintended weight loss, or comes with blood in the stool is more likely to have a structural or inflammatory cause that needs investigation beyond symptom-based diagnosis.
How Diagnosis Differs in Children
Evaluating stomach pain in kids presents unique challenges. Young children often can’t describe or localize their pain well, symptoms tend to be vague, and the classic presentations adults show are less reliable. Examining a young child works best in a parent’s lap, and doctors often distract the child while feeling the abdomen to get a more accurate read on tenderness.
The likely causes also shift by age. In infants under one year, the most common surgical causes are incarcerated inguinal hernia (about 45% of cases) and intussusception (about 42%), a condition where part of the intestine folds into itself. In children over one year, appendicitis dominates, accounting for roughly 64% of surgical abdominal diagnoses.
Imaging choices also differ. Ultrasound is the preferred first-line imaging for children with suspected surgical conditions. Both the American College of Radiology and the American College of Emergency Physicians recommend against routine CT scans for suspected appendicitis in children until ultrasound has been tried first, specifically to limit radiation exposure in developing bodies. CT is reserved for critically ill pediatric patients or cases where ultrasound is inconclusive.
Red Flags That Signal an Emergency
Certain features of abdominal pain indicate a potentially life-threatening situation. Sudden, severe pain that makes you unable to sit still or find a comfortable position, a rigid abdomen that feels board-like to the touch, signs of shock (rapid heart rate with low blood pressure), high fever with worsening pain, vomiting blood, or passing black tarry stools all warrant immediate emergency evaluation. In women of childbearing age, sudden lower abdominal pain with vaginal bleeding or missed periods raises concern for ectopic pregnancy, which can cause dangerous internal bleeding. Abdominal pain following trauma, even if it seems mild at first, can indicate internal organ injury that worsens over hours.