Why Do People Have Seasonal Allergies?

Do you suffer from allergies? Researchers estimate about 50 million people in the U.S. suffer from allergies. About 40 percent of all children and 30 percent of adults are affected. A person is more likely to suffer from allergies if they live in a highly industrialized area or if their relatives suffer from allergies. Symptoms of seasonal allergies include sneezing, itchy and swollen eyes, and a runny nose. The cause of these allergies has do to with your immune system.

Seasonal allergies occur when your body has a hypersensitive immune response to environmental substances that aren't actually harmful. For instance, pollen is a fine powder produced by trees, flowers, grasses, and weeds. It's not harmful. Yet, when pollen finds its way into your mucus membranes, your body may attack the tiny spores and treat it as infectious bacteria. Your immune system has then tagged the foreign spores as threatening, and your white blood cells produce customized antibodies that fight them anytime they come around. The antibodies turn on mast cells, which release chemicals like histamine that cause swelling and other allergy symptoms.

Sources: WebMD, Ted-Ed