Swelling and pain in the right back under the ribs is usually considered to be caused by chest wall diseases, urinary system and digestive system diseases. 1. Chest wall diseases: As people are usually right-handed, the right side muscles are often in a state of stress, so the right side muscles of the back are easy to be over-fatigued, resulting in strain; trauma can lead to the right back soft tissues and ribs fracture, resulting in the right back ribs and subcostal swelling and pain. 2. Urological diseases: Since there are organs such as kidneys and ureters under the right rib cage of the back, it is considered that kidney stones may cause pressure on the ureters, thus triggering pain. 3. Digestive system diseases: Since organs such as liver and gallbladder also exist on the right side of the body, subcostal distension caused by liver and gallbladder system diseases cannot be excluded. In addition, a very small number of skin and ligament diseases can also cause swelling and pain in the right back under the ribs, therefore, if the symptoms are more serious, you should consult a doctor in time, carry out relevant examinations to clarify the cause of the disease and then treat it actively.