Lung cancer is caused by the pollution of respiratory air. Pollutant that most often becomes cause of lung cancer is cigarette's smoke or dust that related with work, such as asbestos, nickel, chrom, ether and coal's smoke.
In lung cancer, cancer cells spread in bronchus surface and spread to another body part. Symptom produced by it is chronic cough with bloody mucus, breath produces sound, it happens infection in the lung, and it often found liquid in pleuritic cavity.