The symptoms of chest pain in the morning are most likely triggered by thoracic rib arthritis. The human body is completely immobile except for the first thoracic rib joint, which is connected by cartilage union. The second through seventh sternocostal joints are connected by fibrocartilage and ligamentous attachments to the sternum and rib cartilage, and because they do not have an articular cavity, the sternocostal joints are not very mobile, although they can move. Because of the cartilage structure of the sternocostal joint, the blood circulation is relatively poor, so once the chest changes shape excessively, or the upper limb lifts heavy objects for a long time, or one limb repeatedly performs excessive activities, the ligaments and fibrocartilage around the sternocostal joint may be damaged and local inflammation may be induced. After a night’s sleep and rest, the blood circulation around the thoracic and rib joints will become worse due to inflammatory stimulation, and when you suddenly move your chest after waking up in the morning, you will have obvious pain symptoms.