What is an Allergy?

An allergy is an abnormal reaction by a person's immune system against what would normally be considered a harmless substance. A person who is not allergic would have no adverse reaction such a substance, but when a person who is allergic finds themselves exposed to such a trigger, the body reacts by sending out chemicals known as histamines, which causes the symptoms associated with an allergic reaction.

When speaking of such allergic reactions, we are frequently talking about allergic rhinitis. Allergic rhinitis is an inflammation of the nasal passages, usually accompanied by runny nose, sneezing and itching of both the nose and eyes.

Another type of allergic reaction, and one that can be deadly in fact, is anaphylaxis. The symptom is often a dramatic swelling and closing of the airways. This is more typically associated with food or drug allergies, as well as from biting or stinging insects such as bees or wasps. Fortunately, this is not the common reaction we speak of here, but instead requires specialized medication and doctor care.

As well, some clarification is in order. Simply because there is exposure to a substance and a subsequent reaction involving symptoms, does not necessarily mean that a person is suffering an allergic reaction to that substance. One such example can be found when taking medications which are known to have side effects. Thus, a person exhibiting such side effects is not necessarily allergic to that medication.