 Tobacco use leads most commonly to diseases affecting the heart and lungs, with smoking being a major risk factor for heart attacks, strokes, chronic obstructive pulmonary disease (COPD), Idiopathic Pulmonary Fibrosis (IPF), emphysema, and cancer (particularly lung cancer, cancers of the larynx and mouth, esophageal cancer and pancreatic cancer).Cigarette smoking increases the risk of Crohn's disease as well as the severity of the course of the disease.It is also the number one cause of bladder cancer.