Most of early lung cancers will not have obvious abnormalities, only some patients will have clinical manifestations such as cough, fever and chest distension. 1. Coughing, although the size of early tumor is small, it is still a foreign body, which will repeatedly stimulate the bronchial and pulmonary tissues, thus causing irritating coughing due to rejection reaction, which is only mild and not very frequent. 2. Fever, if the tumor volume is large and causes obstruction to the lung lobe, the patient will have fever, generally the patients with good physique will have low fever; those with poor physique will have high fever. 3. Chest distension, early tumors will also stimulate and squeeze the lung tissues, thus causing chest distension and chest pain.