An allergy is an immune system response to a foreign substance that's not typically harmful to your body. These foreign substances are called allergens. They can include certain foods, pollen, or pet dander. Your immune system's job is to keep you healthy by fighting harmful pathogens.

Allergy symptoms

• Sneezing and an itchy

• Runny or blocked nose

• Itchy, red, watering eyes

• Wheezing, chest tightness, shortness of breath and a cough

• Shortness of breath and a cough

• Swollen lips, tongue, eyes or face

Allergies are a condition in which the body's immune system overreacts to certain substances and triggers an allergic reaction. The 10 most common allergies include foods, animals, pollen, mold, dust mites, medications, latex, insect stings, cockroaches, and perfumes/household chemicals.