Asthma is the commonest chronic childhood disease and encompasses a spectrum of airway diseases with similar symptoms. Inaccurate diagnosis remains common, especially in younger children, with failure to characterize the different “asthmas.” Children worldwide repeatedly suffer symptoms which severely affect their everyday lives. Children die from asthma, especially in low and middle-income countries (LMICs). In many countries, asthma prevalence is rising. Access to effective care and changing environments are hugely variable and may explain the higher morbidity in inner-city children, in LMICs, and in deprived populations in high-income countries. Despite the disease being eminently controllable, morbidity and mortality persist.