10 Worst Cities for Allergies and Why

More than 50 million Americans live with nasal allergies. An allergy is an immune system response to foreign substances called allergens. You could be allergic to something you ate, touched, breathed in, or injected into your body. Allergies usually cause sneezing, itchy eyes, sneezing, a scratchy throat and a runny nose. Severe allergies can cause hives, low blood pressure, rashes, asthma attacks, trouble breathing and even death.

Although over the counter medications are available to help deal with the symptoms, allergies have no cure.