WebMD 1:01: How Do Allergies Work?

Allergies. They can have a big impact on your life.

Oh, I know. I once dated this amazing guy who had a cat. I'm allergic. So he had to decide between me and the cat.

Which did he choose?

The cat, Noah. Donald picked the cat. OK? Now, let's learn about these allergies that ruined my life. Allergies happen when your immune system thinks a substance, like stupid pet dander, is a dangerous intruder.

When a person with allergies is exposed to an allergen-- through food, insect bites, or even pollen-- the body produces a large quantity of antibodies.

Those antibodies then cause some cells to release chemicals into the bloodstream, one of which is histamine.

The histamine then acts on the eyes, nose, throat, lungs, skin, or gastrointestinal tract, and causes the symptoms of an allergic reaction.

[SNEEZES] Stupid histamines.

Hey, come on. They're only trying to help. Whatever. Reactions can range from mild to severe, where emergency medical treatment is needed. But most of the time, some medication will do the trick.

And people can be allergic to almost anything, from foods to medications to grass, ragweed, to animal dander, from dogs and cats-- Katz's Deli-- ca-- nondogs.

Cats. You can say it. Cats. I am over Donald and that dumb Mr. Snugglebottoms.

Yeah. Clearly. [MUSIC PLAYING]