Hereditary angioedema (HAE) is a condition that results from an autosomal dominant trait. It manifests as attacks of swelling involving the extremities, trunk, abdominal viscera, face, neck, or airway. The attacks may occur spontaneously, without any identifiable trigger, or may be the result of a specific trigger, such as a minor tissue trauma. The symptoms of an attack range from abdominal discomfort to a swelling of the upper extremities to a laryngeal edema that can lead to severe airway obstruction. Therapy for HAE can be divided into three distinct phases: treatment for acute attacks, short-term prophylaxis, and long-term prophylaxis. Treatment for an acute attack is largely supportive, including administration of epinephrine and antihistamines to maintain a patent, reliable airway. Shortterm prophylaxis includes fresh frozen plasma and corticosteroids. Long-term prophylaxis includes use of androgens and antifibrinolytics, as well as the avoidance of known triggers. Prior to the advent of such therapies, mortality from an acute attack of HAE was reported as high as 30%. Repeated episodes of unexplained cutaneous edema or abdominal discomfort may be caused by HAE. The nurse's role focuses on prevention of complications and supportive care, as well as education of the patient to minimize risk factors that may cause further episodes.