Ayurveda describes the biological fire of the body required for all the metabolic functions (chemical processes for digestion of food) as ‘Agni’.[i] The food that we eat gets digested and absorbed from the stomach every day, which is important for the maintenance of life. This is performed by Agni.[ii] Agni is the invariable agent in the process of Paka (digestion, transformation). Ingested food which is to be digested, absorbed and assimilated, and is unavoidable for the maintenance of life, is performed by the Agni.

Agni converts food in the form of energy, which is responsible for all the vital processes of our body. Therefore, Ayurveda considers that Dehagni is the cause of life, complexion, strength, health, nourishment, lusture, teja (energy), oja and prana (life energy).

If Tridoshas (vata, pitta and kapha) are in homeostasis, this equilibrium is responsible for Samagni (agni in harmony). Digestive activity gets affected when these three doshas become aggravated, imbalanced or severe.[iii] When the Pitta is higher than normal, the condition is known as Tikshnagni. When Vata and Kapha are greater than normal, the condition is known as Mandagni.