What is anaphylaxis?
Anaphylaxis (say "anna-full-ax-iss") is a life-threatening allergic reaction. It starts soon after you are exposed to something you are severely allergic to. You may have swelling, itching or a rash. Some people have trouble breathing, a tight feeling in their chest or dizziness. Some people feel anxious. Other people have stomach cramps, nausea or diarrhea. Some people lose consciousness ("pass out").
Written by familydoctor.org editorial staff