This article presents the complexity of asthma and its ensuing management. The author details the clinical presentation of asthma, discussing its variability of presentation over time and within and among individuals. Pathophysiology is discussed, including immunohistopathologic features and inflammatory mediators, risk factors, comorbid conditions, natural history, and triggers. Diagnosis is presented in light of the challenging history of patients suspected of the disorder; pulmonary function testing, symptom assessment, impairment assessment, and risk assessment. Categories of asthma severity, controlling triggers, pharmacotherapy, stepwise approaches, and ongoing assessment are discussed, with a review of a clinical trial assessing efficacy of management.