Allergies is a catch-all term for an immune response of the body to a specific substance that is referred to as an "allergen" and which may manifest as a variety of symptoms such as skin reactions, sneezing, watery eyes and nasal congestion. Common allergens are pollen, dust, mould/fungus, and even foods. Many natural health products can relieve the symptoms of an allergic response but one should be tested to determine the source of the allergen.