You sneeze. You cough. You itch. And you wait for allergy season to end so you can sleep well, or make it through five minutes without blowing your nose. For millions of allergy sufferers, these symptoms are punishment for a body out of whack, but some researchers say the opposite—allergies form a useful line of defense against the world around us. Researchers from Yale University, in an article published in the journal Nature, argue that allergic responses are a way for the body to defend against harmful or irritating substances in the environment. The purpose of allergies comes down to three basic mechanisms: prevent a substance from getting into your body, getting rid of a substance that made it through your defenses, or encouraging you to avoid the substance. For example, common symptoms of seasonal allergies—increased mucus in your nose and lungs, sneezing, and hiding inside—are ways for your body to block, expel, or avoid things like pollen in the environment. Similar effects happen with skin and food allergies. While pollen doesn’t seem that deadly, there may be other substances in the environment that are more harmful. Allergic responses, though, provide your body with several ways to keep you safe. In some cases, as with severe food allergies, the reaction can be deadly. This type of anaphylactic shock involves swelling of the mouth or throat, and even breathing problems. The researchers say this is a sign of the allergic reaction gone wild. Unfortunately, this doesn’t provide any immediate benefits for allergy sufferers. Still, next time you are sneezing in the middle of ragweed pollen season, remind yourself that your body is doing its best to protect you.