How do i know if i have allergy?

YOu will have an : reaction to something like hives, rash, you will get blow up like a balloon, or your throat might close up, making it hard to breath (anaphylactic shock). To play it safe, if this happens after eating something or having a bee sting, go to the ER and get treated. Then get yourself allergy tested by an allergy doctor to find out what your specific allergy is.