When a body’s immune system reacts abnormally to some substance, it is called as an allergy. Some people’s immune system abnormally responses to some substances, which is not harmful to the other’s body. The allergies occur when the body is exposed to an allergen substance by swallowing it, inhaling it or just a skin touch. Sometimes, allergy is also caused due to food consumption or insect bite. The different symptoms of allergies are watery eyes, itching, sneezing, runny nose, vomiting, diarrhea, swelling, soreness, rashes, stomach cramps, tiredness and illness. The allergy can affect an organ, tissue or the entire body. The symptoms of an allergic reaction, stops when the body is away from the exposure.