The symptoms of back pain after coughing up phlegm may suffer from bronchitis, pneumonia and other diseases. 1. Bronchitis: it can be caused by biological or non-biological factors, patients cough, cough sputum as the main manifestation, when the patient coughing symptoms are more serious, it can pull the back muscle groups, resulting in pain in the back. 2. Pneumonia: Bacterial pneumonia and viral pneumonia are the most common. Patients usually have the typical manifestations of coughing and sputum, and in severe cases, even blood in sputum and dyspnea. If the pneumonia is close to the chest wall and involves the pleura of the back, it may cause back pain. 3. Other diseases: such as tuberculosis, lung tumors, pulmonary infarction, etc., will also appear symptoms of coughing, coughing up sputum, and if the coughing is severe, it will lead to pain in the chest or back area. All in all, coughing, sputum, back pain, it is recommended to consult a doctor in a timely manner, and follow the doctor’s instructions for symptomatic treatment.