There are five main possibilities for the pain on the right side of the chest: first, chest trauma, mostly with a clear history of chest impact, manifested as chest swelling and pain with the formation of skin spots. Secondly, costochondritis, which usually occurs in the 2-4 intercostal space, with clinical symptoms mainly being stabbing pain in the chest, and the pain is mostly aggravated after exertion or exposure to cold. Third, pleurisy, often secondary to lung infection, manifests as a limited dull pain in the chest and the pain is aggravated by deep breathing or violent coughing. Fourth, breast hyperplasia, a common benign disease of the breast, is clinically manifested by the formation of bead-like nodules in the breast and is accompanied by breast swelling and pain that changes with the menstrual cycle. Fifthly, lung cancer, which is common in middle-aged and old-aged patients with a history of smoking, manifests as chest stabbing pain accompanied by irritating cough or hemoptysis, and should be treated promptly when the right side of the chest hurts and actively cooperate with the specialist to avoid further aggravation.