When a foreign substance such as pollen, dust mites and cat dander enters the body, allergic reaction occurs after the body becomes sensitized to these substances. The first time an allergen is inhaled the body recognizes it as an invading substance. Cells located under the mucus membranes in the nose make large amounts of antibodies against them. The most common type of antibody associated with pollen is Immunoglobulin (IgE). The next time these allergens invade the body these antibodies release special chemicals such as histamines to combat them. These substances cause the nearby tissues to become swollen and inflamed which triggers all the different kinds of symptoms experienced during Hay fever onset. Common treatment remedies such as Anti-histamines avoid the release of histamine which prevents the common symptoms.