Allergy and asthma due to abnormal immune system, which mistakenly react to foreign subtances that are typically harmless to most people. The allergy-producing subtances are also known as allergens which include pollens, drugs, dust mite, perfumes, animal hair,molds, a particular food, certain chemicals or even a change in outside temperature. Allergy causes release of histamine into the bloodstream, thrn acts on a person’s eyes,nose,throat,lungs,skin, or gastrointestinal tract and causes the symptoms of the allegic reaction.

Allergic diseases are major public health problem in many industrialized contries. Over the last three decades allergic diseases have significantly increased with an upward trend. The increase has been noted both for children and adults across all social classes.

Allergy, however has become a very common disease in almost every family. For example skin allergy appears as reddish and itchy patches,swollen and itching eyes and allergic rhinitis or hay fever causes sneezing and running nose, food allergy that causes bloating or stomach discomfort after ingesting the allergen. In lungs or respiratory system, the asthma attack is often due to some allergen that is breathed into the lung.

Asthma is a common disease in the young and old, yet most people do not know that asthma is usually due to allergies in the lungs. Asthma is a chronic disease that affects your airways. If you have asthma, the inside walls of your airways become sore and swollen and may react strongly to things that you are allergic. At the end, airways get narrower and your lungs get less air resulting in wheezing, coughing, chest tightness and trouble breathing. More severe case, people can die due to insufficiency of oxygen in vital organs.

It is widely recognized that the incidence of allergies is on the rise globally. The role of nutrition in allergy and asthma are correlated to antioxidant vitamins A,C,E and selenium. Thus, they enchance respiratory functions, improves allergic symptoms and asthmatic conditions.Scientific studies have found a relationship between the low blood levels of ascorbic acid and the frequency and severity of asthmatic attacks. High dose vitamin C may help reduce asthmatics by lowering histamine levels and then linked to a better respiratory health. In ancient China, ginkgo was used to relieve asthma, as it has the pharmacology effects of dilating the bronchiole to relieve and prevent asthma attacks.