The human body has several ways of eliminating toxins. In a healthy body, if an allergen such as pollen enters the system it is captured by the mucosal lining of the respiratory tract and evicted from the body through the nose or mouth. However, if the mucosal barrier is unable to eliminate the allergen, the body responds by increasing the production of mucus, in minor cases causing irritation to even major breathing problems in severe cases.

There are also allergic reactions where swellings of certain body parts, rashes, and more problems are seen. Based on the type of allergies, they are classified into vatha, pitta, and kapha, and the diet has to be changed according to the type of dosha. Ayurveda suggests several healing programmes for allergic reactions which are intended to reduce the intensity of the reaction towards the allergen and remove the toxin build up from the body.