Hereditary angioedema (HAE) types I and II are autosomal dominant conditions characterized by recurrent attacks of edema formation in the subcutaneous tissue of the body or walls of the upper respiratory or gastrointestinal tract. Frequently, prodromal symptoms occur before an HAE attack. If certain prodromal symptoms were determined to be both sensitive and specific in predicting an acute HAE attack, treatment at the time of the prodrome could prevent development of an attack and decrease morbidity and mortality associated with HAE. The goal is to determine the frequency and timing of prodromal symptoms occurring before HAE attacks. After Institutional Review Board approval, a four-page survey was produced, using a focus group of patients with HAE and was assessed by HAE patients and physicians with expertise in HAE for cognitive reliability. Once devised, the questionnaire was sent to 158 HAE patients. The survey focused on questions related to prodromal symptoms that patients developed before their last HAE attack. Forty-six patients returned the survey and 40 (87.0%) reported the presence of prodromal symptoms before their last HAE attack. Forty-four of 46 (95.7%) reported having had prodromal symptoms before HAE attacks in the past. The most commonly reported prodromal symptoms included unusual fatigue, rash, and muscle aches. Prodromes occur frequently before HAE attacks. This high frequency suggests that prodromal symptoms could be a reliable indication to begin treatment to prevent an acute HAE attack, thus decreasing the anxiety associated with having an HAE attack.