More than 10.4 million visits were made to U.S. emergency rooms for abdominal pain in 2010, reports the Centers for Disease Control and Prevention. The causes of abdominal pain are many and range from self-limited to life-threatening. Pain felt in the right upper region of the abdomen -- known as the right upper quadrant, or RUQ -- often arises from organs in this area. However, other, more distant organs may also direct pain to this region.
Located beneath the liver in the RUQ, the gallbladder is a small organ that stores bile. Gallstones sometimes block bile flow out of the gallbladder, causing stretching of the organ and RUQ pain. Inflammation of the gallbladder, known as cholecystitis, may also cause pain in this area. Although rare, cancer of the gallbladder or major bile ducts is another possible cause of pain in this region.
Located in the RUQ, the liver is the largest solid organ in the body. It has a capsule with many nerve endings located along the surface. Conditions that stretch the liver capsule often trigger pain. Liver inflammation, or hepatitis, can develop from numerous causes. Viruses, abnormal fat accumulation in liver cells and excessive alcohol consumption commonly cause liver inflammation and pain.
Pockets of infection, called abscesses, can also enlarge and stretch the liver capsule. In some cases, infection from the female reproductive organs spreads to the liver capsule, causing pain. Similarly, liver cancer may stretch the liver capsule and trigger RUQ pain.
Though a less common cause, inflammation of the colon -- known as colitis -- can trigger RUQ pain. This may be a result of infection or an inflammatory bowel disease, such as Crohn disease. Diverticulitis is a type of colitis that occurs in weak areas of the colon known as diverticula, which are outpouchings in the bowel wall. It is more common in the left lower quadrant but can occur in other areas of the bowel. Irritable bowel syndrome may cause generalized or local abdominal pain, which may involve the RUQ.
The diaphragm and the right lung are directly above the RUQ of the abdomen. Although the lungs are not in the abdomen, nerve endings may direct pain into the RUQ, a phenomenon known as referred pain. Pneumonia in the lower lobe of the right lung, in particular, can result in local pain. Other pulmonary conditions that lead to inflammation of the lining around the lungs, called pleurisy, may trigger abdominal pain. Pleurisy is often caused by viral infections but could also be the result of more serious conditions such as pulmonary embolism, where a blood clot goes into the lungs.
The kidneys are a pair of organs located in the back of the abdomen. Diseases that cause inflammation of the right kidney may lead to RUQ pain. Kidney and urinary tract infections can be associated with abdominal pain, back pain, and burning with urination. Kidney stones can irritate the urinary tract or block urine flow from the kidneys. This blockage may cause the kidneys to become inflamed and enlarged, triggering pain. Cysts on the kidneys can also cause discomfort by stretching the tissue over the kidneys.
The pancreas is in the upper middle abdomen, but may cause RUQ pain via referred pain. Pancreatic inflammation may occur when gallstones block ducts leading to the pancreas or with alcohol abuse, potentially causing RUQ pain.
People who have had surgery or trauma to the abdomen may develop scar tissue called adhesions. Adhesions can disrupt normal anatomy and cause nerves to travel to areas they would not otherwise go, potentially causing pain in the RUQ.