Pain in the left upper lung is mostly due to the following causes: First, trauma to the left upper lung. Trauma to the left upper lung can lead to local muscle and bone pain. Second, lung diseases, pneumonia, tuberculosis, lung tumors can lead to pain in the left upper lung, which should be further diagnosed by chest X-ray or chest CT examination. Third, left pleural disease, including pleurisy, pleural tumor can lead to pain in the left upper lung, and the pain is obvious when inhaling deeply or coughing, CT examination should be done to further clarify. Fourth, heart disease, heart disease, such as coronary heart disease, angina pectoris, etc. can lead to pain in the upper left chest, such as this patient often has a history of heart disease, often accompanied by chest tightness, panic, palpitations and other symptoms, can do electrocardiogram, cardiac ultrasound and other tests to further clarify.