AbstractUrticaria and angioedema are common disorders that can severely impair the quality of a patient's life and can be extremely difficult to treat. Symptoms can persist for years to decades. The causes of urticaria and angioedema are varied and may be immunologic, nonimmunologic, or idiopathic. This article reviews the literature and provides primary care physicians with up‐to‐date information of the epidemiology, basic pathophysiology, diagnosis, and management of this common and often debilitating condition. Additionally, clinical manifestations of acute and chronic urticaria, hereditary and acquired angioedema, as well as the physical urticarias will be discussed. Mt Sinai J Med 78:784–802, 2011. © 2011 Mount Sinai School of Medicine