The pain in the left side of the rib cage is like a forked gas, which is usually acute chest and rib pain, mainly due to improper posture and excessive force during exercise, causing local stagnation of qi and blood, which leads to pain in the chest and rib cage, which increases with breathing and coughing, exertion, turning side, and activity, without any damage to the skin surface. The pain may also be caused by excessive stretching of the gastrointestinal tract after exercise after meals, so pay attention to adjusting the breathing rhythm.