The edema itself usually lasts for twenty four to seventy two hours, but the length of an attack can range from four hours to four days. Swelling of the extremities is uncomfortable and, according to some patients, can be painful depending on the location of the edema. Attacks that involve the face and throat must be taken seriously and medical treatment should be sought without delay. Swelling of the throat can close the air passage and cause death by suffocation. The symptoms of an impending airway obstruction include difficulty swallowing and a change in voice pitch.
Abdominal attacks cause severe pain, nausea, vomiting, and watery diarrhea.
Some patients require hospitalization for low blood pressure, dehydration, and pain management. As noted above, abdominal attacks can mimic a surgical abdomen and many patients have been subjected to unnecessary exploratory surgery. There are three types of therapy for HAE patients. Long term therapy is not required for all HAE patients. In some patients attacks are mild or infrequent and no long-term therapy is required.