What are allergies?

Allergies occur when your body has an exaggerated response to a harmless substance (like dust) that it mistakenly perceives as an invader (like a virus). The immune system reacts by releasing antibodies to attack the harmless substance, known as an allergen. Antibodies trigger the release of histamine and other chemicals in the body that cause symptoms of allergies, such as itchy eyes, runny nose, nasal congestion, itchy skin, and hives.

Allergies are a result of overactive immune systems reacting to relatively harmless substances, such as dust and pollen, as they were invading bacterium or viruses.

Allergies occur when our body's immune (defense) system reacts to something harmless in our environment. Inhalation allergies like pollen can cause mild symptoms, such as red eyes, itching, hives or runny nose. Food allergies are more likely to cause a wide assortment of symptoms (fatigue, pain, nasal congestion, migraines, spastic colon, autism, and many more), and should be considered when your doctor does not know the cause of a problem. In rare cases they can be life threatening (anaphylaxis where the throat swells shut or shock can occur) as occurs in some peanut allergies. For those with the latter type, carrying an "Epi-pen" (preloaded adrenaline syringe) can be life saving.

Allergies, by definition, are a reaction to the body seeing something as "foreign." As a result, any part of your body that comes into direct contact with the environment around us or the things we breathe or ingest can cause an allergic reaction. Allergic symptoms include dry or itchy skin, hives, runny nose, or itchy, red eyes, shortness of breath, nausea, vomiting or diarrhea, or even swelling of your tongue or throat in more severe reactions.