The swelling sensation under the right rib cage may be caused by muscle strain, liver disease, costochondritis and so on. 1. Muscle strain: long time work or labor, easy to muscle damage, so that the patient has muscle soreness and swelling, so the right side of the ribs below the swelling may be muscle soreness and swelling. 2. Liver disease: such as chronic hepatitis, liver cysts, etc., the patient will also have a sense of swelling under the right side of the rib cage, usually accompanied by pain. 3. Costochondritis: Patients with costochondritis mainly have swelling and pain in the chest area, which may also radiate to the right side of the lower ribs, usually due to trauma or viral infection. In addition to the above factors, it may also be caused by other reasons, it is recommended that patients go to the hospital in time for examination, with the help of doctors to clarify the causes, and then targeted treatment.