​Your body reacts in a certain way when exposed to a harmful environment, and that reaction is called allergy. Scientifically speaking, your immune system produces a hypersensitive response to a foreign substance(s) when it enters and comes into contact with the body. These substances are known as allergens and can be anything, from plants, mites, pets, and molds to medicines or a particular food.

The type of allergies that affect a person may differ from body to body, and the most common symptoms are rashes, itching, sneezing, watery and itchy eyes, and nasal congestion.