Lung cancer is the leading cause of cancer death among men and women. Because the most common risk factor for lung cancer is smoking, most of these deaths might have been prevented. Inhaled tobacco smoke damages the cells that line the bronchi or air passages, a process many doctors believe represents an early stage of cancer. The first symptoms -- coughing or wheezing -- may be mistaken as smoker's cough. Blood-stained mucus may also be expelled. Other symptoms may include weight loss and chest pain, and in the more advanced stages, hoarseness and shortness of breath. The best way to avoid lung cancer is not to smoke. Other risk factors include exposure to industrial substances such as asbestos and coal gas, and the involuntary breathing in of tobacco smoke by nonsmokers. The primary treatments for lung cancer are surgery, radiation, and chemotherapy, depending on the type of cancer and stage of the disease. If you experience any symptoms of lung cancer, contact your physician without delay.