RUQ pain is pain in the right upper quadrant of your abdomen, the area below your ribs on the right side. It’s one of the most common reasons people visit an emergency room or urgent care, and the cause is most often related to the gallbladder or liver. But several other organs sit in this region, and the source of the pain isn’t always obvious without imaging.
What’s in the Right Upper Quadrant
Your right upper quadrant contains a surprisingly dense cluster of organs. The right lobe of the liver takes up the most space, with the gallbladder tucked underneath it. The first section of the small intestine (the duodenum), the head of the pancreas, the right kidney and its adrenal gland, and part of the colon all sit in this quadrant too. Pain originating from any of these structures can feel like it’s coming from the same general area, which is why pinpointing the cause often requires imaging rather than a physical exam alone.
Most Common Causes
Gallbladder Problems
Gallbladder disease is the single most frequent cause of RUQ pain. It falls into two main categories. Biliary colic happens when a gallstone temporarily blocks the duct leading out of the gallbladder. This produces episodes of intense, crampy pain that typically last less than six hours and then resolve on their own. The pain often starts after a fatty meal.
Acute cholecystitis is more serious. It happens when a gallstone gets stuck and the gallbladder becomes inflamed. The pain feels similar to biliary colic but is more severe, peaks within 15 to 60 minutes, and then persists as a constant ache for six hours or longer. Nausea, vomiting, and fever are common. Repeated episodes of gallstone blockage can lead to chronic cholecystitis, where the gallbladder wall thickens and stops functioning well over time.
Liver Conditions
The liver itself doesn’t have pain receptors inside its tissue. Instead, liver-related pain comes from the thin capsule that surrounds it. When the liver swells from hepatitis, congestion, or an abscess, that capsule stretches and triggers pain receptors in the surrounding membrane. This is why liver pain tends to feel like a dull, deep ache rather than a sharp stab. It can worsen when you lie on your left side, because gravity pulls the swollen liver away from its supporting ligaments and stretches the capsule further.
Kidney Issues
A kidney stone lodged on the right side or a kidney infection (pyelonephritis) can both produce pain that overlaps with the right upper quadrant, though the pain often wraps around toward the back or flank. Kidney stone pain tends to come in waves, while infection pain is more constant and accompanied by fever, chills, and painful urination.
Less Obvious Sources
Not all RUQ pain originates in the abdomen. Right-sided pneumonia or a blood clot in the lung can both cause pain that feels like it’s coming from under the ribs. Colitis or inflammation of the colon’s right side is another possibility. These diagnoses are easy to miss when the initial suspicion focuses on the gallbladder or liver.
Pain That Spreads to the Right Shoulder
One distinctive pattern with RUQ pain is radiation to the right shoulder or shoulder blade. This happens because the nerve that supplies sensation to the diaphragm (which sits directly on top of the liver and gallbladder) also supplies the shoulder area. When the diaphragm gets irritated by inflammation below it, your brain interprets some of that signal as shoulder pain. If you have right shoulder pain with no obvious injury, especially alongside nausea or abdominal discomfort, the source may actually be your gallbladder or liver.
RUQ Pain in Specific Populations
During Pregnancy
RUQ pain during pregnancy deserves immediate attention because it can signal HELLP syndrome, a dangerous complication related to preeclampsia. HELLP involves the breakdown of red blood cells, elevated liver enzymes, and low platelet counts. Upper right abdominal pain is one of its hallmark symptoms, particularly in the third trimester or shortly after delivery. If you’re pregnant and develop RUQ pain along with headaches, vision changes, or swelling, treat it as urgent.
In Younger Women
Fitz-Hugh-Curtis syndrome is an underrecognized cause of RUQ pain in women of childbearing age. It develops as a complication of pelvic inflammatory disease, when infection travels upward and inflames the liver capsule. The pain worsens with movement and breathing, mimicking gallbladder disease. Clues that point toward this diagnosis include concurrent pelvic pain, abnormal vaginal discharge, fever above 38.3°C (about 101°F), and a history of sexually transmitted infection.
How RUQ Pain Is Evaluated
An abdominal ultrasound is the standard first test when you show up with RUQ pain. It’s fast, doesn’t involve radiation, and is excellent at detecting gallstones, gallbladder wall thickening, bile duct blockages, and basic liver abnormalities. The American College of Radiology recommends ultrasound as the initial imaging choice for suspected biliary disease.
When the cause isn’t clear from ultrasound, or the suspicion extends beyond the gallbladder, a CT scan with contrast is considered equally appropriate as a first-line option. CT is better at identifying problems like abscesses, blood clots in the lungs, kidney stones, and masses. In some cases, a specialized nuclear medicine scan may follow if cholecystitis is suspected but the ultrasound results are ambiguous, since that scan has higher accuracy for detecting gallbladder inflammation specifically.
During the physical exam, your provider will likely press on the area below your right ribs while you take a deep breath. A sharp catch of pain when the inflamed gallbladder meets the examiner’s fingers is called Murphy’s sign. It’s a useful clue, but it’s not definitive on its own. Even when performed during ultrasound, this test catches about 86% of acute cholecystitis cases while producing a fair number of false positives.
Warning Signs That Need Immediate Care
Most RUQ pain turns out to be manageable, but certain combinations of symptoms signal a potential emergency. A rigid abdomen that feels board-like when touched suggests something may have perforated or that the lining of the abdomen is severely inflamed. High fever with RUQ pain and yellowing of the skin or eyes (jaundice) can indicate a bile duct infection called cholangitis, which can progress to sepsis quickly. A rapid heart rate, lightheadedness when standing, or feeling faint alongside abdominal pain points to possible internal bleeding or the early stages of shock. RUQ pain with any of these features warrants emergency evaluation rather than a wait-and-see approach.