What causes allergic reactions?
"Whether it's runny, itchy or stuffed, your nose knows what's bothering it. But do you know what's wrong with your nasal passages? Understanding allergies isn't difficult, but it is the first step toward building a healthy alliance with your nose, eyes, lungs, and sinuses."
What Causes Chronic Allergies?
"If you've got allergies, you might wonder what to expect in the long term. Are you stuck with allergy symptoms, or will they get better? Or could they actually get even worse?"
"When you have a food allergy, your immune system mistakenly identifies a specific food or a substance in food as something harmful."
Pollen Allergies: How Does Pollen Cause Allergies?
"Pollen consists of tiny, egg-shaped, powdery grains released from flowering plants, which are carried by the wind or insects and serve to cross-pollinate other plants of the same type for reproductive purposes. When pollen is present in the air, it can land in a person's eyes, nose, lungs and skin and cause an allergic reaction."