It's an extreme response to an allergen.

A life-threatening allergic reaction (anaphylaxis) is a severe reaction to a specific allergen, or allergic trigger. Common triggers can include but are not limited to food, biting or stinging insects, medications and latex. Exercise-induced anaphylaxis is also possible, and sometimes anaphylaxis has no apparent cause at all (this is known as idiopathic anaphylaxis).


Click on one of the following triggers to learn more about it:

What happens inside the body when anaphylaxis occurs?

Anaphylaxis occurs when the body perceives a trigger as a threat and starts forming antibodies (special proteins made by the body’s immune system) to defend itself. These antibodies cause the release of certain molecules that produce the immediate symptoms of anaphylaxis.

Want a better understanding of how anaphylaxis works? Watch our video below for a quick overview.

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What is anaphylaxis?
Anaphylaxis is the medical term for a life-threatening allergic reaction that can occur within minutes to several hours after your immune system mistakenly overreacts to certain allergens. It can be triggered by a particular food, biting or stinging insects, medication, latex, and a variety of other substances.

Anaphylaxis can involve multiple body systems, including the mouth, throat, heart, lungs, and stomach, in addition to the skin symptoms commonly experienced during an allergic response.

When someone has an allergic reaction, their body releases special molecules including histamines that interact with blood vessels causing them to expand. This expansion can trigger symptoms like hives, itching, swelling, and low blood pressure.

The opposite occurs in the person’s airway and the arteries that supply their heart. They may narrow causing respiratory or cardiovascular symptoms, such as trouble breathing, chest pains, or fainting.

Because severe allergic reactions can occur within minutes of exposure to allergens, make avoiding them your number one priority and learn to identify the signs and symptoms of anaphylaxis.