The following are common causes of right-sided pain under the rib cage: 1. superficial lesions: such as costochondritis, intercostal neuralgia, etc., may manifest as right-sided discomfort; 2. gallbladder lesions: because the gallbladder is located on the right side of the lower rib cage, acute cholecystitis, often manifest as acute right upper abdominal pain, accompanied by fever, nausea, vomiting and other manifestations, chronic cholecystitis also manifest as intermittent right upper abdominal discomfort; 3, Liver lesions, various acute and chronic hepatitis, fatty liver caused by various reasons, drug-related liver injury, autoimmune liver disease, etc., may lead to discomfort on the right side of the lower ribs; 4, digestive system lesions: such as inflammation of the gastrointestinal tract, or gastrointestinal diseases caused by ischemia, may lead to discomfort in the right upper abdomen.