The most common cause of pain under the right breast is localized inflammation of the rib cartilage or intercostal neuralgia, usually due to strenuous exercise or exertion followed by external exposure to wind, cold and dampness, resulting in a local inflammatory reaction. The pain is characterized by localized tingling, swelling, and sometimes radiating pain along the rib cage to the back and other areas. For this condition, the best treatment is to use local heat therapy, such as hot water bags or hot towels, and infrared therapy can be used for treatment if available. If the pain is severe, you can also apply topical Fotarine ointment or take oral non-steroidal anti-inflammatory and analgesic drugs, such as Xilabao capsules or Nimesulide dispersible tablets. The second cause may be hepatobiliary disease, such as cysts in the liver, hemangioma or cholecystitis, which may cause vague pain or swelling in the area below the right breast or the upper edge of the rib cage. In this case, we should actively improve the ultrasound examination of the abdomen to make a clear diagnosis and then choose the appropriate treatment plan according to the condition.