Having phlegm all the time is not necessarily lung cancer, but may also be caused by chronic pharyngitis or laryngitis, pneumonia and other reasons. 1. Lung cancer: there may be no obvious clinical manifestations in the early stage; if the disease develops further, cough, sputum, chest tightness, low-grade fever, emaciation, chest pain, etc. The sputum may have blood or blood clots in it. There may be blood or blood clots in the sputum. 2. Chronic pharyngitis or laryngitis: cough and sputum symptoms may also occur, may also be accompanied by throat pain or itching, foreign body sensation and other symptoms, but the lung symptoms are not serious, no obvious emaciation and other tumor manifestations. 3. Pneumonia: cough and sputum symptoms can occur, although the nature of sputum is different for different pathogens, such as Klebsiella pneumonia, brick red jelly-like sputum, usually accompanied by high fever, chills and other manifestations, the use of new antibiotics for specific pathogens, such as the use of aminoglycoside antibiotics for Klebsiella bacteria such as Gentamicin, the symptoms can be improved after treatment. Prolonged cough and sputum, it is recommended to go to the hospital. If you have the habit of smoking, it is recommended to quit in time.