Stomach pain is one of the most common reasons people visit an emergency room, accounting for about 10% of all noninjury ER visits in adults. The good news: roughly 83% of those visits don’t result in a serious diagnosis. The challenge is that your abdomen contains dozens of organs packed closely together, so pain in this area can mean anything from a mild case of indigestion to something that needs urgent attention. Where the pain is, how it feels, and how it behaves over time are the biggest clues to what’s actually going on.
Why Stomach Pain Feels Vague
Your internal organs have far fewer pain-sensing nerve endings than your skin, and those nerve endings are spread further apart. This is why abdominal pain often feels dull, achy, and hard to pinpoint, unlike the sharp, precise pain you’d feel from a cut on your finger. Your brain simply isn’t as good at mapping where the signal is coming from inside your body.
This also explains referred pain, where a problem in one organ creates a sensation somewhere else entirely. A gallbladder issue can cause pain in your right shoulder. A heart attack can feel like upper stomach pain. The wiring between your organs and your brain isn’t always a straight line, which is why location alone doesn’t always tell the full story.
When pain shifts from dull and spread out to sharp and localized, that’s typically a sign the problem has progressed. Dull, widespread discomfort usually involves the organ itself. Sharp, focused pain means the inflammation or irritation has reached the lining of your abdominal wall, which has a much denser network of nerves.
What Location Tells You
Where you feel pain narrows the list of possible causes significantly. While this isn’t a substitute for a professional evaluation, the general patterns are well established.
Upper Right Side
Pain here most commonly involves the gallbladder, often from gallstones or gallbladder inflammation. It can also stem from liver problems, kidney stones, or even a lower lung condition like pneumonia. Gallbladder pain typically flares after fatty meals and may radiate to your right shoulder blade.
Upper Left Side
This area houses the stomach, spleen, and pancreas. Acid reflux and gastritis are the most frequent culprits, producing a burning sensation that may worsen after eating. Pancreas inflammation causes a deeper, more intense pain that often radiates straight through to the back. In some cases, upper left abdominal pain can be cardiac in origin, particularly if it comes with shortness of breath or chest pressure.
Lower Right Side
The classic concern here is appendicitis. The textbook pattern starts as vague pain around the belly button that migrates to the lower right side over several hours, getting steadily worse. But appendicitis isn’t the only possibility. Inflammatory bowel disease, irritable bowel syndrome, and kidney stones all produce pain in this area. In women, ovarian cysts, ovarian torsion, and ectopic pregnancy are important considerations.
Lower Left Side
Diverticulitis is one of the most common causes of lower left abdominal pain, especially in people over 50. Pouches in the colon wall become inflamed or infected, causing steady pain that often comes with fever. Irritable bowel syndrome, inflammatory bowel disease, and kidney stones also cause pain in this region. As with the right side, reproductive organ conditions in women can present here.
Pain All Over or Around the Belly Button
Widespread abdominal pain that’s hard to locate is often related to gas, a stomach virus, food poisoning, or early-stage conditions that haven’t yet localized. Pain centered around the belly button can signal early appendicitis before it migrates, or a small bowel issue.
Acid Reflux vs. Ulcers
These two conditions are commonly confused because both cause upper abdominal discomfort, but they behave differently. Acid reflux (GERD) produces heartburn, a burning feeling in the center of the chest, often with regurgitation of stomach contents, bad breath, nausea, or difficulty swallowing. It tends to worsen when you lie down or bend over after eating.
Ulcers cause a gnawing or burning pain in the upper abdomen, but not always. Some ulcers are painless. When pain is present, it may improve briefly after eating (because food buffers the acid) and then return. Ulcer pain is generally more localized to one spot in the upper abdomen, while reflux creates a broader burning sensation that travels upward.
Stomach Pain in Women
Women experiencing lower abdominal pain face a wider diagnostic picture because reproductive organs sit in the same region as the intestines and urinary tract. Conditions like endometriosis, ovarian cysts, pelvic inflammatory disease, and ectopic pregnancy can all feel like general stomach pain. Some women have more than one pelvic condition contributing to their pain at the same time, which makes the picture even murkier.
Ovarian torsion, where an ovary twists on its blood supply, causes sudden and severe lower abdominal pain and is a surgical emergency. Ectopic pregnancy, where a fertilized egg implants outside the uterus, can produce lower abdominal pain with vaginal bleeding and is life-threatening if it ruptures. Any sudden, severe lower abdominal pain in a woman of reproductive age warrants immediate medical evaluation.
How Age Changes the Picture
The same symptom can mean very different things depending on your age. In younger adults, stomach pain most often traces back to relatively common conditions: gastritis, irritable bowel syndrome, urinary tract infections, or appendicitis.
In older adults, the stakes rise. Surgical intervention for abdominal pain occurs twice as often in older patients compared to younger ones. Conditions that barely register in a younger person can become dangerous in someone over 65. About half of people over 45 have some degree of plaque buildup in the arteries supplying the intestines, which raises the risk of mesenteric ischemia, a condition where blood flow to part of the gut is cut off. The hallmark is severe pain that seems out of proportion to what a doctor finds on physical exam.
Abdominal aortic aneurysm is another concern in older adults, particularly men who smoke or have high blood pressure. A rupturing aneurysm causes severe abdominal or back pain with a drop in blood pressure. The classic combination of low blood pressure, back pain, and a pulsating mass in the abdomen is present in only 25 to 50% of cases, meaning it’s often missed without imaging.
Cancer-related bowel obstruction also becomes more likely with age. Malignancy is the most common cause of large bowel obstruction in older patients, and symptoms tend to develop gradually: increasing constipation, bloating, weight loss, and eventually vomiting.
When Stomach Pain Is an Emergency
Most stomach pain resolves on its own or with simple treatment. But certain patterns signal something more serious. ER physicians look for pain that has lasted more than five minutes and is getting worse rather than staying the same or improving. Pain that escalates steadily is far more concerning than pain that comes and goes.
Alongside the pain itself, these accompanying symptoms raise the urgency:
- Fever, which suggests infection or inflammation
- Vomiting blood or bloody/black stools, which suggest bleeding in the digestive tract
- Blood in the urine, which may point to kidney stones or a urinary tract problem
- Pain with urination, which suggests infection
- A rigid, board-like abdomen, which can indicate a perforated organ or severe infection of the abdominal lining
- Rebound tenderness, where the pain is worst when pressure on the abdomen is released rather than applied
Sudden, severe pain that hits like a switch being flipped is also concerning. This pattern is more typical of a ruptured cyst, a perforated ulcer, or a torsion (twisting) of an organ than it is of a stomach bug.
What Happens During a Workup
If your stomach pain is severe enough or persistent enough to warrant medical evaluation, the diagnostic approach follows a logical sequence based on where the pain is and what’s most likely causing it.
Ultrasound is the first imaging test for right upper quadrant pain, since it’s excellent at spotting gallstones and gallbladder inflammation. It’s also the go-to for women of reproductive age when a gynecologic cause is suspected, and for pregnant patients, because it doesn’t involve radiation. For lower abdominal pain on either side, a CT scan with contrast is the standard. CT is also what doctors turn to when the diagnosis is unclear after a physical exam and blood work, or when there’s real concern about something serious like appendicitis, diverticulitis, a bowel obstruction, or an abscess.
Blood tests and urine tests typically come first and help narrow the field. A pregnancy test is routine for women of reproductive age with abdominal pain, because ectopic pregnancy can be life-threatening and mimics many other conditions. From there, imaging fills in the picture. In many cases, the combination of your pain’s location, your symptoms, a physical exam, and basic lab work is enough to reach a diagnosis without advanced imaging at all.