A high number of people in the United States visit emergency rooms and are admitted to hospitals every year due to having an asthma condition. Individuals who have asthma have to live with the knowledge that at any time, they may suddenly, and often without warning, be barely able to breathe. An asthma attack occurs when there is a sudden obstruction of the bronchial tubes, and generally is due to an exposure or triggering factor. Three complex pathologic processes found in asthma, involving hypersensitivity of the bronchial passages, airway inflammation, and airway obstruction are discussed. Asthma can be a temporary disease but for many people, it is chronic and without a cure. There are effective treatments and methods of prevention available for people who live with asthma.