Abdominal pain has dozens of possible causes, ranging from something as simple as trapped gas to conditions that need urgent treatment. Most cases aren’t serious. CDC data from emergency departments show that only about 17% of visits for abdominal pain result in a serious diagnosis. But the location, timing, and character of your pain can tell you a lot about what’s going on and whether you need to act quickly.
Where the Pain Is Matters
Your abdomen is divided into rough quadrants, and each one houses different organs. Pain in the upper right side, near your rib cage, often points to your gallbladder or liver. Pain in the upper middle or left side may involve your stomach, pancreas, or spleen. Lower right pain raises concern for appendicitis, while lower left pain in adults over 40 frequently suggests diverticulitis. Pain that’s hard to pin down or sits around the belly button could be related to your intestines, a stomach virus, or something functional like irritable bowel syndrome.
These patterns aren’t rules. Pain can radiate, shift, or start in one place and settle in another. Appendicitis, for example, classically starts as a vague ache around the belly button before migrating to the lower right side over several hours. Gallbladder pain can radiate to the upper back or even behind the breastbone, which sometimes gets mistaken for heart trouble.
Common Causes of Upper Abdominal Pain
A steady, gripping pain in the upper right abdomen near the rib cage is the hallmark of gallstone trouble. When a gallstone temporarily blocks the duct leading out of the gallbladder, you get episodes of intense pain that can last anywhere from 30 minutes to a few hours, then resolve. This is called biliary colic. If the blockage persists and the gallbladder becomes inflamed, the pain becomes constant, lasts for days, and often gets worse when you take a deep breath. You may also develop a fever. That progression from intermittent to persistent pain is a key distinction between a gallstone episode and active gallbladder inflammation.
Pain in the upper middle abdomen that gets worse after eating may point to your pancreas. Acute pancreatitis typically causes pain that bores through to the back, along with nausea, a swollen or tender belly, fever, and a rapid pulse. The pain can start mild and build, or hit suddenly and severely.
Gastritis, ulcers, and acid reflux also live in the upper abdomen. These tend to produce a burning or gnawing sensation, often related to meals or an empty stomach. Ulcer pain that suddenly becomes severe and constant could mean the ulcer has perforated, which is a surgical emergency.
Common Causes of Lower Abdominal Pain
In the lower right, appendicitis is the diagnosis no one wants to miss. The classic pattern is pain that starts around the belly button, then shifts to the lower right side over 12 to 24 hours. Loss of appetite, nausea, vomiting, and a low-grade fever often accompany it. The area becomes increasingly tender to touch, and pressing on it then quickly releasing (rebound tenderness) makes the pain spike. If you’re experiencing this combination, get evaluated promptly. Appendicitis can progress to a rupture within 48 to 72 hours of symptom onset.
In the lower left, diverticulitis is the leading concern, especially if you’re over 40. Diverticulitis happens when small pouches in the colon wall become inflamed or infected. Left lower quadrant tenderness is the most telling physical finding. You may also have fever, bloating, or changes in bowel habits. Notably, vomiting is uncommon with diverticulitis, which can help distinguish it from other causes. The condition is rare before age 40 (affecting less than 10% of that group) but becomes extremely common with age, present in roughly 80% of people over 85.
Causes Specific to Women
Lower abdominal pain in women has an additional set of possibilities related to the reproductive organs. Ovarian cysts can cause sudden, sharp pain on one side, especially if a cyst ruptures or twists. Endometriosis produces pain that often tracks with the menstrual cycle but can become chronic.
Pelvic inflammatory disease, an infection of the uterus, fallopian tubes, or ovaries, causes lower abdominal pain along with fever, foul-smelling vaginal discharge, bleeding between periods, or pain during sex. It’s most commonly caused by sexually transmitted bacteria and needs antibiotic treatment to prevent long-term complications like infertility.
Ectopic pregnancy, where a fertilized egg implants outside the uterus, is a true emergency. It causes severe abdominal pain, often on one side, along with vaginal bleeding. If you’re of reproductive age, have lower abdominal pain, and there’s any chance you could be pregnant, this possibility should be ruled out quickly.
When the Pain Keeps Coming Back
Not all abdominal pain has a clear structural cause. Irritable bowel syndrome is one of the most common reasons for recurring belly pain, affecting an estimated 10 to 15% of the population. For a formal diagnosis, you need to have recurrent abdominal pain at least one day per week for three months, with symptoms that started at least six months earlier. The pain is typically linked to bowel movements and comes with changes in stool frequency or consistency (more constipation, more diarrhea, or both).
IBS doesn’t damage the intestines or show up on imaging. It’s a disorder of gut-brain communication, which means the gut is more sensitive to normal stimuli like gas or stretching. That doesn’t make the pain less real. It does mean the treatment approach focuses on dietary changes, stress management, and sometimes medications that calm gut nerve signaling rather than surgery or antibiotics.
Other recurring causes include food intolerances (lactose and fructose are common culprits), chronic constipation, inflammatory bowel diseases like Crohn’s and ulcerative colitis, and peptic ulcers. If your pain follows a predictable pattern tied to certain foods, stress, or your menstrual cycle, that pattern is valuable information for figuring out the cause.
How Doctors Figure Out the Cause
The diagnostic approach depends heavily on where your pain is and how severe it is. For upper right abdominal pain, ultrasound is the first imaging test because it’s excellent at detecting gallstones and gallbladder inflammation. For lower abdominal pain on either side, CT scan is preferred because it picks up appendicitis, diverticulitis, and other conditions with high accuracy. CT with contrast has a sensitivity of 94% and specificity of 99% for diverticulitis, meaning it catches nearly all cases and rarely gives a false positive.
Blood work, urine tests, and sometimes stool samples help narrow the possibilities. A pregnancy test is standard for women of reproductive age with lower abdominal pain, regardless of what they report about contraception use. In many cases, especially for mild or chronic pain, your doctor may start with a physical exam and basic labs before ordering imaging.
Pain That Needs Immediate Attention
Most abdominal pain resolves on its own or with simple treatment. But certain features signal a potential emergency:
- Sudden, severe pain that doesn’t ease within 30 minutes. This can indicate a perforated ulcer, ruptured aneurysm, or ruptured ectopic pregnancy.
- Pain with a rigid abdomen. If your belly feels hard and board-like, and touching it anywhere causes severe pain, that suggests irritation of the abdominal lining.
- Continuous vomiting alongside severe pain, which may indicate a bowel obstruction or pancreatitis.
- Pain with high fever and rapid heart rate, suggesting an active infection or abscess.
- Tearing or ripping sensation in the abdomen or back. A ruptured abdominal aortic aneurysm produces sudden, devastating pain that feels like something is tearing apart. This is most relevant for older adults, smokers, and those with a history of high blood pressure.
- Severe abdominal pain with vaginal bleeding in a woman who could be pregnant.
If your pain is mild to moderate, started gradually, and you can still eat, drink, and move around, it’s reasonable to monitor it for a day or two. If it worsens, changes location, or new symptoms develop, that’s your signal to get checked.