When would you consider hereditary angioedema attacks serious?

Close the airway. Hereditary angioedema is characterized by episodes of tissue swelling in the face, throat, limbs, and abdomen. In most cases, the swelling develops over hours but sometimes it may take only minutes. The most serious attacks swell the throat closed which can quickly cause respiratory arrest & death if not treated. Frequent & unpredictable attacks are also serious and require preventative treatment.