Anaphylaxis is usually the result of an allergy, although on rare occasions it can be caused by exercise. When your body comes in contact with something you're allergic to, it overreacts by sending out antibodies to neutralize the allergen -- even though it's not actually dangerous. While the symptoms of an allergic response are generally just unpleasant, anaphylaxis is an uncommon yet life-threatening allergic symptom. Among its most dangerous aspects are extremely low blood pressure, difficulty breathing and loss of consciousness.

The most common culprits behind anaphylaxis are certain foods, drugs and insect stings. In terms of foods, peanuts, tree nuts, shellfish, dairy and eggs are the ones most frequently responsible for anaphylactic reactions. Penicillin is the drug most associated with anaphylaxis, but other antibiotics and anti-seizure medications are also known to cause dangerous reactions. If you remember the 1991 movie "My Girl," you remember the dangers of bee stings (the young girl in that movie dies after getting stung). Beyond bees, other venomous insects associated with allergy-induced anaphylaxis are wasps, hornets, yellow jackets and fire ants. Some highly sensitive people have anaphylactic reactions to latex or anesthetics as well. The least common but medically proven cause of anaphylaxis is exercise; for some people, even mild exertion like walking or gardening can set off an anaphylactic reaction. While not actually an allergic version of anaphylaxis, some people get anaphylaxis from aspirin or other nonsteroidal anti-inflammatory drugs and the intravenous dye used in certain types of X-ray tests.

When anaphylaxis sets in, you must seek medical attention right away. If you carry an epinephrine autoinjector with you, that's the time to use it. Epinephrine is an adrenaline that helps your body calm the anaphylaxis before it progresses to a more dangerous stage. Medical professionals often give intravenous antihistamines and cortisone in addition to epinephrine to treat anaphylaxis.