What are allergies?

The purpose of this guide is to help readers understand what allergies are, their symptoms, and what can be done to treat them.

An allergy is an over-reaction by the body's immune system. People who have allergies have a hyper-alert immune system that over reacts to substances, such as pollen, called allergens. About twenty percent of Americans suffer from allergies and it's the 6th leading chronic disease in the United States. Not everyone gets allergies, but most of them are inherited. People don't inherit any specific allergy, but just a tendency to be allergic to any number of substances.


There are different degrees of allergic reactions. The degrees of allergic reactions are mild, moderate, and severe. The more common allergic reactions are often categorized as mild reactions. Mild allergic reactions only affect parts of the body such as the skin, nose, or eyes.

Mild reactions contained to the nose include swelling and allergic rhinitis. Dust mites feces and body parts are also responsible for the cause of allergic rhinitis. Allergic reactions localized to the skin include rashes, hives and "contact" dermatitis. Allergic reaction localizations distinct to the eyes are redness and itching of the membrane that covers the eyes and lids.

Moderate reactions are a bit more severe, but are not life-threatening. These types of reactions are commonly associated with airway restrictions. Symptoms associated with moderate allergic reactions are wheezing, difficulty swallowing, possibly asthma attacks, and constriction of the bronchial tubes.

The most severe allergic reactions are categorized as severe anaphylaxis; these types of reactions, rare as they may be, are very life-threatening. They usually begin with one part of the body such as the eyes, then it spreads to your mid-section to include symptoms such as craps and abdominal pain. Soon, a person suffering from anaphylaxis will begin to vomit, have diarrhea, and different degrees of swelling which can make swallowing or breathing hard. Anaphylaxis also causes a sharp decrease in blood pressure which may cause mental confusion.

Allergic Substances

There many allergic substances that can cause allergic reactions; this chart we have created shows what substances may cause allergic reactions in some people.

FoodInsectPlantDrugAnimal bi-products
Nuts X
Egg white X
Peas X
Solk products X
wheat X
Ragweed X
Birch Trees X
Mold spores X
Rye grass X
Poison ivy X
Wasp stings X
Jelly stings X
Bee stings X
Penicillin X
Anaesthetics X
Salicylates X
Pet dander and hair X X
Dust mite feces X