Hereditary angioedema (HAE) is a rare but important disease because of the occurrence of life-threatening symptoms during attacks as well as due to diagnostic and therapeutic problems. Deficiency or absence of plasma protein--C1 esterase inhibitor is autosomal dominant condition and is connected with uncontrolled complement and contact systems activation which leads to the generation of vasoactive mediators, most likely bradykinin. The main syndromes are recurrent attacks of localized swelling of submucosal and subcutaneous tissue, or both. In consequence skin and visceral organs may be involved by the typically massive local edema without pruritus. Authors discuss epidemiology, pathophysiology, genetics and classification of angioedema also with regard to its triggers and localization. This paper also reviews clinical symptoms diversity, diagnostic methods and type differentiation for HAE.