How to distinguish early lung cancer from pneumonia

This is mentioned in Liu Ye's Persistence of Cancer. The main symptom of early lung cancer is cough, which is characterized by paroxysmal irritating choking, unclean feeling, generally no sputum or only a small amount of white foam sputum, and purulent sputum may appear when secondary infection occurs. If there is no improvement after 2 weeks of anti-inflammatory treatment, we should be alert to the possibility of lung cancer. Or the nature of cough has changed on the basis of the original chronic cough, even accompanied by "tracheal sound" and "shortness of breath", which should be paid attention to. Another warning sign of lung cancer is intermittent repeated small amount of blood sputum, or bloodshot sputum. In addition, there are symptoms such as chest pain, chest tightness and fever!