Right side pain has dozens of possible causes, and the most likely one depends heavily on where exactly you feel it. Pain just below your ribs points to a different set of organs than pain near your hip bone, and the quality of the pain (sharp, dull, crampy, constant) narrows things further. Here’s a breakdown of the most common causes organized by location, what each one feels like, and what to watch for.
Upper Right Side: Gallbladder, Liver, and Bile Ducts
The most common cause of pain in the upper right abdomen, just beneath or behind the ribs, involves the gallbladder. Gallstones affect roughly 10 to 15 percent of adults, and when a stone temporarily blocks the duct leading out of the gallbladder, it produces a distinctive pattern called biliary colic. This pain typically starts 20 minutes to a few hours after eating, especially after a large or fatty meal. Fat in your small intestine triggers the gallbladder to squeeze, and if a stone is in the way, that contraction causes intense, building pain. An episode can last anywhere from 20 minutes to several hours.
If a gallstone stays lodged and the gallbladder becomes inflamed, the condition progresses to cholecystitis. More than 75 percent of people with acute cholecystitis have right upper quadrant pain or colic, and about 65 percent have a specific sign where pressing under the right ribs while breathing in causes a sharp catch of pain. Fever often accompanies the inflammation. Ultrasound is the first-line imaging test for evaluating this kind of pain.
The liver itself doesn’t have pain-sensing nerves inside it, but it’s wrapped in a thin capsule that does. When the liver swells from hepatitis, congestive heart failure, or another condition, that capsule stretches and produces a deep, aching discomfort under the right rib cage. The pain travels through nerve fibers that run alongside the major blood vessels entering the liver, which is why it can sometimes feel vague or hard to pinpoint.
Lower Right Side: Appendicitis and Intestinal Causes
Appendicitis is the classic cause of lower right abdominal pain, and it’s one of the most common surgical emergencies. It typically starts as a vague ache around the belly button, then migrates over 12 to 24 hours to the lower right, settling near a spot roughly one-third of the way from the hip bone to the navel. The pain tends to be constant rather than crampy and gets worse with movement, coughing, or jarring. Rebound tenderness, where releasing pressure hurts more than pressing in, raises suspicion, though its diagnostic accuracy varies.
Other intestinal causes of right-sided pain include Crohn’s disease, which commonly affects the last section of the small intestine (located in the lower right abdomen) and can mimic appendicitis in a flare. Right-sided colon problems, including diverticulitis on the right side (less common than on the left, but it happens), infections, and inflammatory conditions can also cause pain here. In rare cases, a segment of bowel can telescope into itself, a condition that accounts for less than 5 percent of bowel obstructions in adults but can cause significant right-sided pain when it involves the junction between the small and large intestine.
Right Flank: Kidney Stones and Infections
Pain that starts in the back, just below the ribs on the right side, and wraps around toward the front often originates in the right kidney. Kidney stones produce sudden-onset, intense, colicky flank pain that can radiate downward into the groin, testicle, or labia as the stone moves through the ureter. Nausea and vomiting are common, and most people also have blood in their urine, even if it’s only visible under a microscope.
A kidney infection (pyelonephritis) causes flank pain too, but it tends to be more constant than colicky and comes with fever, chills, and painful urination. Both kidney stones and kidney infections show up in the differential diagnosis for right upper quadrant pain because the right kidney sits just behind the liver, and the pain zones overlap.
Pelvic Causes in Women
For women, right-sided pelvic pain has its own set of causes that involve the right ovary and fallopian tube. A ruptured ovarian cyst can cause sudden, sharp pain on one side that improves over hours to days. Ovarian torsion, where the ovary twists on its blood supply, produces severe, often sudden pain with nausea and is a surgical emergency.
Ectopic pregnancy, where a fertilized egg implants in the fallopian tube instead of the uterus, causes one-sided pelvic pain that can become life-threatening if the tube ruptures. A pregnancy test below certain thresholds does not reliably rule it out, so any woman of reproductive age with unilateral pelvic pain and a missed period needs evaluation. Pelvic inflammatory disease is another common cause: studies show that 20 to 50 percent of women presenting with pelvic pain are found to have PID, particularly when there is tenderness during a pelvic exam with no other clear explanation.
Lung and Chest Wall Causes
Pain felt on the right side of the torso doesn’t always originate in the abdomen. Pneumonia in the lower right lung can produce pain that feels like it’s coming from the upper abdomen, especially when the infection irritates the lining between the lung and the diaphragm. A pulmonary embolism (blood clot in the lung) can do the same. Both belong in the differential for right upper quadrant pain, and they’re worth considering when the pain worsens with deep breathing or when there’s a cough, shortness of breath, or fever.
Muscle and Abdominal Wall Pain
Sometimes right-sided pain comes not from an internal organ but from the abdominal wall itself: the muscles, nerves, or connective tissue. A pulled muscle, a nerve entrapment, or even a hernia can produce localized pain that mimics something more serious. One useful distinction is the Carnett test: if you press on the sore spot and then tense your abdominal muscles (like doing a partial sit-up), pain from the abdominal wall stays the same or gets worse, while pain from an internal organ typically decreases because the tensed muscles shield the organs underneath.
Slipping rib syndrome is another underdiagnosed cause. It involves the lower ribs shifting slightly and irritating nearby nerves, producing pain in the lower chest or upper abdomen. A hooking maneuver, where curved fingers pull forward under the rib margin, reproduces the pain and helps identify it.
Signs That Warrant Emergency Evaluation
Certain features of right-sided pain signal something that needs immediate attention:
- Pain so severe it interrupts your ability to function, especially if it came on suddenly
- Uncontrollable vomiting or an inability to keep liquids down
- Fever with abdominal pain, which suggests infection or inflammation
- A rigid, board-like abdomen that is exquisitely tender to touch
- Pain that resembles previous episodes but is clearly worse or different in character
- History of abdominal surgery combined with new pain and inability to pass stool or gas, which could indicate a bowel obstruction from adhesions
Right-sided pain that is mild, comes and goes, and has an obvious trigger (like a hard workout or a large meal) is less concerning than pain that is new, worsening, or accompanied by any of the features above. The location, timing, and associated symptoms are the most useful clues in narrowing down what’s going on.