Hereditary angioedema affects approximately 1 in 50,000 individuals without gender or ethnic preference. Hereditary angioedema is caused by a decreased level (type I) or function (type II) of C1 inhibitor. Patients experience repeated episodes of angioedema involving sites that include the face, extremities, gastrointestinal tract, and larynx. Treatment involves measures to increase functioning levels of active C1 inhibitor through stimulation of endogenous pathways or exogenous supplementation. Additional therapies targeted at inhibition of bradykinin can also be used to treat episodes of angioedema. Treatment may be indicated for both acute episodes of angioedema and prevention of future episodes.