According to WebMD, 2 in 10 Americans suffer from some kind of seasonal allergies. Allergies are caused by abnormal responses by your immune system to a typically harmless substance. Any time your body is exposed to these substances, known as an “allergen” (pollen, pet dander, ragweed, dust, etc.), immune system cells known as “mast cells” release a substance called histamine. Histamine attaches to receptors in the blood vessels causing them to swell and irritate. This reaction creates the itchy sensation in the eyes and nose associated with allergies.

It’s been determined that allergies are inherited genetically. However, you don’t inherit allergies to specific substances, only the propensity to be allergic. Over time, as your body and immune system are exposed to different allergens, your immune system responds to each substance and sometimes an allergic reaction happens. Based on the substance your reaction could be different. If your allergen is carried on the air (dust, pollen, dander, etc), your reaction will take place in the eyes, nose and throat, generally. If your reaction is to a food substance (eggs, peanuts, or shellfish, for example), your reaction will generally take place in the mouth, throat and/or stomach.

Serious, full-body reactions are possible with severe allergies. These reactions create a condition known as anaphylaxis and serious medical aid must be rendered when these attacks occur. Anaphylaxis happens mostly with food allergies, but can happen with airborne allergens as well.