The place where the arm and chest are connected hurts, causing diseases mainly include the following aspects: 1. Consider that it is caused by soft tissue strain or muscle damage etc. adjacent to the arm and chest, mostly due to long-term lifting of the upper limbs or lifting and holding heavy objects etc., resulting in the place under the arm and chest, mainly the intercostal muscle meat and other muscle strain, which in turn causes pain. For this cause of pain, you need to apply massage, massage, as well as hot compresses, physical therapy, etc., can be alleviated. If the pain is severe, you can use topical anti-inflammatory drugs to relieve pain, such as blood circulation and blood stasis, as well as topical spraying of fotarine; 2. Consider that it is caused by intercostal chondritis or intercostal neuralgia, where the arm is connected to the chest, there is intercostal cartilage and intercostal nerve, etc. If you do not pay attention to the usual activities or local cold, it can cause intercostal chondritis or intercostal neuralgia; 3. Consider that it is caused by trauma and other rib fractures, trauma and other causes The continuity of the rib bone is destroyed, which causes pain, and it is necessary to go to the hospital for chest X-ray examination, which can be clarified.