Abdominal pain has dozens of possible causes, ranging from mild gas and constipation to serious conditions like appendicitis or a ruptured ovarian cyst. Where you feel the pain, how long it lasts, and what other symptoms accompany it are the strongest clues to what’s going on. Abdominal pain is one of the most common reasons people visit an emergency department, accounting for roughly 7 million visits per year in the United States alone.
Where the Pain Is Matters
Your abdomen is divided into four quadrants, each housing different organs. Pain that stays in one area often points toward a specific organ, while pain that moves or spreads across the whole belly suggests something more general.
Upper right: This quadrant holds your gallbladder, liver, and the upper part of your right kidney. Pain here most commonly comes from gallstones or gallbladder inflammation, especially after fatty meals. Ultrasound is the first imaging test doctors reach for when you have upper right pain.
Upper left: Your stomach, spleen, and pancreas sit here. Pain in this area can signal a stomach ulcer, acid reflux, or pancreatitis (inflammation of the pancreas, often linked to heavy alcohol use or gallstones).
Lower right: This is where your appendix lives, along with part of your colon and, in women, the right ovary and fallopian tube. Sharp pain that starts near the belly button and migrates to the lower right is the classic pattern for appendicitis. CT scans are the preferred imaging tool for lower quadrant pain.
Lower left: The lower left side contains part of the colon and, in women, the left ovary and fallopian tube. Pain here often comes from diverticulitis (inflamed pouches in the colon wall), constipation, or gynecological issues.
Pain in the center of your abdomen, near the belly button or just below the breastbone, can point to stomach ulcers, acid reflux, early appendicitis, or problems with the pancreas. Pain that seems to cover the entire belly without a clear location is more common with gas, viral stomach infections, or irritable bowel syndrome.
Common Everyday Causes
Most abdominal pain resolves on its own and comes from something straightforward. Gas and bloating are the most frequent culprits, usually triggered by certain foods, eating too fast, or swallowing air. Constipation can cause crampy pain across the lower abdomen, and it’s one of the most common causes in both adults and children. Stomach viruses (gastroenteritis) cause pain alongside nausea, vomiting, and diarrhea that typically clears within a few days. Food intolerances, particularly to lactose or fructose, can cause recurring pain, bloating, and loose stools every time you eat the trigger food.
Chronic Pain That Keeps Coming Back
Pain that persists for more than three months, whether it’s constant or comes and goes, is classified as chronic abdominal pain. About 90% of people with chronic abdominal pain have what doctors call a disorder of gut-brain interaction, meaning their digestive organs look structurally normal but don’t function the way they should. Only about 10% have an underlying physical condition that shows up on tests or imaging.
Irritable bowel syndrome (IBS) is one of the most common causes of recurring abdominal pain. It’s a functional disorder: the gut looks normal on scans and scopes, but the nerves in the digestive tract are hypersensitive, amplifying normal sensations like gas or stool movement into pain. IBS typically causes cramping that improves or worsens with bowel movements, along with alternating diarrhea and constipation.
Inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis, is a different problem entirely. IBD is an autoimmune condition where the immune system attacks the lining of the intestines, causing visible inflammation, ulcers, and sometimes bleeding. Unlike IBS, IBD often causes rectal bleeding, urgent bowel movements, and weight loss. The distinction matters because IBD requires treatment to prevent permanent damage to the intestines, while IBS is managed mainly through diet and stress reduction.
Other conditions that cause chronic belly pain include celiac disease (triggered by gluten), chronic pancreatitis, peptic ulcer disease, and food allergies. Less common but worth knowing: long-term cannabis use can cause a condition called cannabinoid hyperemesis syndrome, which produces cycles of severe nausea, vomiting, and abdominal pain that improve with hot showers.
Causes Specific to Women
Women have additional organs in the lower abdomen that can produce pain men don’t experience. Endometriosis, where tissue similar to the uterine lining grows outside the uterus, causes pain that worsens during menstrual periods and during sex. Ovarian cysts are fluid-filled sacs on the ovaries that often form and resolve without symptoms, but a large or ruptured cyst can cause sudden, sharp one-sided pain.
Ovarian torsion occurs when an ovary twists on its blood supply, producing severe pain that often radiates to the groin. It frequently comes with nausea and vomiting and tends to affect the right side more often. Pelvic inflammatory disease (PID), an infection of the reproductive organs usually caused by sexually transmitted bacteria, produces pain on both sides of the lower abdomen along with unusual vaginal discharge and sometimes painful urination.
Ectopic pregnancy, where a fertilized egg implants outside the uterus (usually in a fallopian tube), is a life-threatening emergency. It causes lower abdominal pain with vaginal bleeding, and any woman of reproductive age with these symptoms needs immediate evaluation. A pregnancy test is one of the first things doctors check for women with acute lower abdominal pain.
Serious and Life-Threatening Causes
Some causes of abdominal pain need urgent treatment. Appendicitis is the most common surgical emergency, typically producing pain that intensifies over 12 to 24 hours and settles in the lower right quadrant. Gallbladder attacks from gallstones cause intense upper right pain that can last hours and radiate to the back or right shoulder blade. Acute pancreatitis causes severe upper abdominal pain that bores through to the back, often triggered by gallstones or heavy drinking.
Kidney stones produce pain that’s often described as the worst people have ever felt. The pain typically starts in the back or side and radiates down toward the groin as the stone moves through the urinary tract. It comes in waves and is usually accompanied by blood in the urine.
Abdominal aortic aneurysm is a rare but dangerous cause. The aorta, the body’s largest artery, can develop a bulge in the section that passes through the abdomen. A growing aneurysm causes deep, constant pain in the belly or back, sometimes with a throbbing sensation near the belly button. If it ruptures, the pain becomes sudden and tearing, blood pressure drops, and the situation becomes immediately life-threatening. Smoking is the strongest risk factor, along with hardened arteries and a history of blood vessel disease.
Abdominal Pain in Children
Children complain of stomach pain frequently, and the cause is usually not dangerous. Constipation is the most common culprit in kids, followed by stomach viruses and stress. In younger children and infants, intussusception, where one part of the intestine telescopes into the section next to it, is a less common but serious cause that produces episodes of intense crying, pulling the knees to the chest, and sometimes bloody stool. Any child with these symptoms needs prompt medical attention.
When Abdominal Pain Is an Emergency
Most belly pain doesn’t require a trip to the emergency room, but certain combinations of symptoms signal something that can’t wait. You should seek emergency care if your pain follows an accident or injury, if you also have chest, neck, or shoulder pain, or if you feel short of breath or dizzy alongside the abdominal pain. Vomiting blood, having black or bloody stool, or finding blood in your urine all warrant immediate evaluation.
A belly that’s swollen and tender to the touch, a high fever with abdominal pain, or persistent vomiting that won’t let up are also signs that something more serious may be happening. Sudden, severe pain that comes on all at once, rather than building gradually, is more likely to represent a surgical emergency like a ruptured organ or twisted bowel.
How Doctors Figure Out the Cause
Doctors start by asking about the location, timing, and character of your pain, along with your other symptoms and medical history. Blood and urine tests help identify infection, inflammation, or pregnancy. From there, imaging depends on what’s suspected. Ultrasound is the go-to test for gallbladder problems and is often the first choice for women with pelvic pain. CT scans are better for evaluating appendicitis, kidney stones, and bowel obstructions. For chronic pain without a clear cause, an endoscopy or colonoscopy may be needed to look directly at the lining of the digestive tract.
If all tests come back normal and the pain has lasted more than three months, a functional disorder like IBS or functional dyspepsia becomes the likely explanation. That doesn’t mean the pain isn’t real. It means the problem lies in how the nerves in the gut communicate with the brain, not in structural damage that shows up on a scan.