Vague swelling and pain in the right rib cage may be caused by trauma, costochondritis, lung cancer, pleurisy, leukemia, osteosarcoma and so on. 1. Trauma: the right side of ribs will be swollen and painful after being violently squeezed and impacted, resulting in rib injury or even fracture. 2. Costochondritis: the rib cartilage at the junction of right sternum and ribs has inflammatory lesions due to chronic strain, infection, trauma and other factors, so there are symptoms of swelling and pain. 3. Lung cancer: the cancer cells of middle and late stage lung cancer invade into chest wall and stimulate the nerves of chest wall, thus causing this symptom. 4. Pleurisy: bacterial infection, tuberculosis, autoimmune disease and other factors lead to pleural inflammatory exudation, adhesion and other lesions, and some patients may realize that their right side ribs are vaguely swollen and painful. 5. Leukemia: malignant proliferation of hematopoietic cells in the bone marrow of the right side of the rib cage, resulting in increased pressure in the marrow cavity, which may also cause this symptom. 6. Osteosarcoma: malignant tumors, such as osteosarcoma, originating in the right side of the rib cage, invade normal tissues and cause this symptom. The vague swelling and pain on the right side of the rib cage may be related to many factors, and it is recommended to consult a doctor for a clear diagnosis.