Allergies occur when your body’s defense system (immune system) overreacts to certain substances. The immune system treats a harmless substance as if it were a harmful germ or virus. Many things can cause this overreaction, including pollens, medicine, food, dust, animal dander, and mold.

Allergies can be mild or severe. Mild allergies can be managed with home treatment. But medicine may be needed to prevent problems.

Managing your allergies is an important part of staying healthy. Your doctor may suggest that you have allergy testing to help find out what is causing your allergies. When you know what things trigger your symptoms, you can avoid them. This can prevent allergy symptoms and other health problems.

For severe allergies that cause reactions that affect your whole body (anaphylactic reactions), your doctor may prescribe a shot of epinephrine to carry with you in case you have a severe reaction. Learn how to give yourself the shot and keep it with you at all times. Make sure it is not expired.