An allergy is when your immune system reacts to something that is harmless to most people. Generally, your immune system protects you from substances that can make you sick. But if you come into contact with something that your immune system views as a threat, it releases a chemical called histamine. This release of histamine and other substances is what causes allergy symptoms.

If you come into contact with a substance that your immune system views as a threat, called an allergen, it responds by releasing a chemical called histamine and other substances. The release of these substances is what causes your allergic reaction. Atopy, or having an atopic predisposition, refers to the genetic predisposition to develop allergic diseases.

Sneezing, wheezing, and itching - you may think what you’re experiencing is normal. Learn about all the ways your allergies can show up and the common symptoms and triggers associated with them. Recognizing the typical signs is a step towards getting some relief.