Instances of swelling around the throat or larynx can cause difficulties in breathing should the swelling obstruct airways. This has been known to cause a large number of fatalities in those afflicted with the disorder. Episodes that attack the gastrointestinal tract can cause a number of complications including dehydration from being unable to keep anything down (which, depending on length of the episode, can prove fatal). Symptoms from GI tract swelling including violent vomiting, intense pain from the midsection, dehydration, and intense exhaustion.