Angioedemas are characterized by the sudden onset of swelling in the deep dermis and subcutis. Their causes include allergic reactions, autoimmune mechanisms, infections and non-allergic/pseudo-allergic hypersensititvity reactions. Angioedemas often occur concomitantly with urticaria. The following topics are discussed in the present book: - Treatment of Allergic Angioedemas - Emergency Therapy for Angioedemas - Clinical Manifestation and Therapy for Hereditary Angioedemas - Treatment of Hereditary Angioedemas in Children - Acute Phase Proteins in Kinin-Induced Angioedema - Bradykinin and the Kallikrein-Kinin System - Drugs Affecting the Kallikrein-Kinin System - RAAS Blockers and Bradykinin Metabolism - Therapeutic Effects of ACE Inhibitors