A difficult airway exists in a patient when conventional face mask ventilation is problematic or tracheal intubation is difficult, requiring advanced airway skills for success. Patient factors such as micrognathia, a short neck, a large tongue, craniofacial abnormalities, pregnancy, and obesity are chronic conditions associated with a difficult airway but do not inherently define a difficult airway. Other conditions such as angioedema, epiglottitis, Ludwig's angina, retropharyngeal abscess, tracheal trauma, traumatic/expanding neck hematoma, and cervical trauma are examples of acute factors that similarly may cause a difficult airway condition to exist. When patients with any of these conditions develop dyspnea or respiratory distress, immediate action is required to avert life-threatening decompensation or permanent debility. Furthermore, these patients can present at any time: a patient with a penetrating neck injury may present to an ED without warning, or a long-term ICU patient with diffuse soft tissue edema and a beard may unexpectedly decompensate and require intubation. Therefore, in a variety of settings, clinicians must be prepared for rapid escalation of care and difficult airway management.