Night shift pain under the left chest may be caused by overwork, pleurisy, coronary heart disease and other reasons. 1. Overwork: If patients work night shifts for a long time, it may lead to lack of sleep and overwork of the body, which may cause hidden pain under the left chest when working night shifts. 2. Pleurisy: when various infections, autoimmune diseases, tumors, trauma and other invasions of the pleura, it will cause inflammation of the pleura, chest tightness, chest pain and fever, dyspnea and other symptoms, which may also lead to the phenomenon of pain under the left chest of the patient working at night. 3. Coronary heart disease: If the patient suffers from coronary heart disease and other myocardial ischemic diseases, the heart’s oxygen consumption increases because of fatigue and emotional excitement, which can easily induce myocardial ischemia and lead to vague pain in the chest. When the patient appears on the night shift left under the chest pain, should promptly go to the hospital, identify the cause of the disease, under the guidance of professional doctors to take targeted treatment.