Cough with phlegm and pain above the left chest may be respiratory diseases, cardiovascular diseases, etc., and should be consulted as soon as possible. 1. Respiratory diseases: such as lung inflammation, tuberculosis, lung cancer, etc. can cause coughing and sputum, and coughing vigorously may pull the upper left chest and cause pain. Chest CT examination can be used to make a clear diagnosis. 2. Cardiovascular disease: for example, acute myocardial infarction, cardiac failure, etc., there will be chest pain, coughing, coughing up sputum, both of which are in critical condition and life-threatening at any time, and need to seek medical treatment as soon as possible. In addition to the above causes, there may be sudden pulmonary embolism, pneumothorax, can also appear chest pain, cough, cough sputum symptoms. When these symptoms occur, you should seek early medical attention and diagnosis and treatment under the guidance of a doctor, so as to avoid delaying the condition.