Allergies are a result of the body's increased sensitivity to common substances in the enviornment. These substances are called allergens. Allergens cause reactions when entering the body through the skin, by inhalation or by injestion. Wind blown pollens from grasses, weeds, trees, mold, animal hair, house dust and foods are all examples of allergens.
When an allergic person is exposed to an allergen, the immune system produces an antibody, called immunoglobulin E (IgE). It is the production of this antibody that eventually causes allergy symptoms; sneezing, runny nose, headaches, stomach cramps, joint paint and others.
The blood drawn Allergy test measures the level of circulating IgE antibody in your blood to specific allergens that were tested from various groups of substances i.e. trees, grasses, weeds, molds, animal dander and foods. The level of antibody to each specific allergen is expressed in numbers ranging from 0 to 5, with 0 being the least amount of antibody and 5 being the highest. As a general rule, the higher the number, the higher the level of circulating antibody to the specific allergen tested was found in your bloodstream.
If you have not been recently exposed to, or injested a particular allergen that you previously tested positive to or suspect you are allergic to, you may have little or no circulating antibody to that substance in your bloodstream at the present time. Remember it is important to always consult your physician when interpreting medical test results and formulating a course of action if you have positive test results.