Frequent sneezing is not a manifestation of lung cancer. Early manifestations of lung cancer include cough, irritating dry cough with no or little sputum. Causes of frequent sneezing include allergic rhinitis, common cold, foreign body in nasal cavity and so on. 1. Allergic rhinitis: contact with dust, willow floss, pollen, cold air or irritating gas causes allergic reaction of nasal mucosa, which can be manifested as frequent sneezing. 2. Common cold: mostly caused by viruses, with a more rapid onset, mainly manifested by nasal symptoms, such as sneezing, nasal congestion, runny nose, etc., mostly as the body’s defensive reflexes. 3. Nasal foreign objects: foreign objects are stuffed into the nostrils by the patient himself or others, or animal foreign objects climb into the nostrils, causing damage to the nasal mucosa, sneezing, unilateral nasal discharge, and the nose is not ventilated and other symptoms. In addition to the above reasons, there may be other reasons for frequent sneezing, and it is recommended to go to the hospital in time to find out the cause of the disease and actively treat it.