Lung cancer (Chapter 36: The Lung: III. Neoplasms) is responsible for more deaths (over 125,000 annually) in the United States than any other type of cancer. Chronic obstructive pulmonary disease (COPD, Chapter 35: The Lung: II. Toxic, Immunologic, & Vascular Diseases), which includes emphysema and chronic bronchitis, is the most common type of lung disease. It is second only to ischemic heart disease as a cause of chronic disability. Both lung cancer and COPD are related to cigarette smoking, which is discussed in Chapter 12: Disorders Due to Chemical Agents.