Asthma has been declared as a disease of major public health importance by the World Health Organization (WHO). An optimal strategy for asthma management and prevention was implemented in 1992 by the Global Initiative for Asthma (GINA) which was constituted by WHO and the National Heart, Lungs and Blood Institute (NHLBI). Asthma has affected 300 million people worldwide and 255,000 people died of asthma in 2005. Each decade prevalence of asthma increases by 50%. The disease is predicted to affect an additional 100 million population by 2025. The present article deals with the detailed review of pathophysiology, classification, diagnosis and management of asthma.