Asthma is one of the most common chronic non-communicable diseases worldwide and is characterised by variableairflow obstruction, causing dyspnoea and wheezing. Highly effective therapies are available; asthma morbidity andmortality have vastly improved in the past 15 years, and most patients can attain good asthma control. However,undertreatment is still common, and improving patient and health-care provider understanding of when and howto adjust treatment is crucial. Asthma management consists of a cycle of assessment of asthma control and riskfactors and adjustment of medications accordingly. With the introduction of biological therapies, management ofsevere asthma has entered the precision medicine era—a shift that is driving clinical ambitions towards diseaseremission. Patients with severe asthma often have co-existing conditions contributing to their symptoms, mandatinga multidimensional management approach. In this Seminar, we provide a clinically focused overview of asthma;epidemiology, pathophysiology, diagnosis, and management in children and adults.