The lungs are responsible for oxygen and carbon dioxide exchange. They perform this vital function whether awake or asleep to supply the body with oxygen. The nose acts as a filter to prevent large pollutants from entering the lungs. Lung cancer is the leading cause of cancer death in both men and women, with smoking being the primary risk factor. Quitting smoking can reduce the risk of lung cancer, with younger individuals seeing greater benefits from cessation. Medications are available to assist with smoking cessation.