Cough and pain under the left rib cage are commonly caused by the following: 1. Patients with lung diseases, such as tuberculosis, lung tumors, and pneumoconiosis, can develop a cough, and it can be accompanied by pain under the left rib cage, often accompanied by chills, fever, and coughing sputum; 2. Pleural diseases on the left side, such as pleurisy and pleural tumors, patients can develop a cough and feel pain under the left rib cage when coughing; 3. Cardiovascular diseases, such as coronary heart disease and cardiovascular diseases, such as coronary heart disease, cardiomyopathy, etc., patients can also present with pain under the left rib cage, and some cases can be combined with a cough. In short, if coughing and left subcostal pain occur and the patient does not improve after rest, he/she should go to the hospital for electrocardiogram, chest CT and other examinations to further clarify the diagnosis.