Asthma is a heterogeneous disease characterized by chronic airway inflammation and variable expiratory airflow limitation. It affects 5–15% of people worldwide and has shown an increasing prevalence over the last decade. The treatment of asthma is well established in current guidelines, with the aim of achieving optimal disease control and preventing acute exacerbations using a stepwise medication approach. Drugs are commonly divided into ‘relievers’, which quickly reverse airway obstruction, and ‘controllers’, which target the underlying inflammation providing long-term control.