Australia has one of the highest rates of asthma in the world affecting about 11% of the population and in 2017/18 was responsible for 38,792 hospital admissions and 389 deaths, many of which may have been preventable. Asthma occurs when there is reversible expiratory constriction of the airways, especially the bronchioles and smaller bronchi, in response to various stimuli associated with a chronic inflammatory process. Today we are joined by Dr Michael Ho, an experienced respiratory physician who discusses: