Allergies

Allergies are caused by the body's overzealous reaction to normally harmless substances. Allergies can be triggered by pollen, animal dander, mold, dust, and insect droppings, or by certain foods or insect stings. Upper respiratory allergy symptoms include runny nose, itchy eyes, coughing, wheezing, and sneezing. Up to 50 million people in the U.S. have allergies.