Life-span, complexion, strength, health, enthusiasm, corpulence, luster, immunity, energy, heat processes and vital breath-all these depend on body-fire. One dies if this fire is extinguished, lives long, free from disorders if it is functioning properly. Gets ill if it is deranged, hence Agni (digestive fire) is the root cause of all.
The food that nourishes Dhatus, Ojas (aurora), strength; complexion etc. depends on Agni because Rasa (juice, fluid) etc. can’t be produced from undigested food.
According to Ayurved theory, there are thirteen types of Agni in the body and mind according to the conversion and the transformation made. The most important of them is the Jatharagni, the gastric fire, responsible for digesting food eaten by correlating hydrochloric acid in the stomach and the digestive enzymes and juices secreted into the stomach, duodenum and the small intestines. If digestive Agni is low and the capacity is impaired, one may experience pain, discomfort, feeling of heaviness or gases gurgling, constipation or loose stools.
Agni and Pitta are closely connected. While both are hot and light, Agni is subtle and dry. The heat energy to help digestion, contained by Pitta is Agni. Pitta is therefore the container and Agni the content. Agni is acidic in nature and stimulates digestion. It is subtly related to the movement of Vata. In every tissue and cell Agni is present and is necessary for maintaining the nutrition and autoimmune mechanism. It destroys microorganisms, foreign bacterias and toxins in the stomach and the intestines.
How Agni works.
The solar plexus is the seat of fire, and this fire principle regulates body temperature. Fire is also responsible for digestion, absorption and assimilation.
The Prana vayu (one of the type of air present in our body) receives and carries the food to the belly where the food, disintegrated by fluids (juices) and softened by fatty substance gets acted upon by the digestive fire fanned by the Samana vayu (one of the type of air present in our body). Thus the digestive fires timely cooks the food and enhances the life span of an individual. Agni cooks from below the food situated in the stomach for division into Rasa (nutritive fraction) and Mala (excretion), much, as the Agni (fire) cooks the rice grains with water kept in a vessel into boiled rice.
The food composed of six Rasa immediately after it is ingested undergoes the stages of ‘prapaka’ (preliminary digestion). Firstly, due to predominance of, sweetness Kapha (mucus secretion) of frothy character arises. Thereafter, during the process of digestion when the food is half-burnt and descending from the stomach due to predominance of acidity Pitta (the bile and other digestive factors) comes forth freely. Lastly, when it reaches the large intestines, it is absorbed by the fire and gets converted into a solid mass, vayu (wind) is formed due to predominance of pungency.
The desired food endowed with desired smell etc. nourishes the sense of smell as well as the olfactory sense etc., individually in the body.
Five Agni pertaining each to Prithvi (earth), Jal (water), Tejas (fire), vayu(air) and Akash (space) digest the respective fractions of the food.
In body, the substances and their properties nourish their counterparts respectively, such as the fraction of Prithvi (earth) in food nourishes the respective fractions in the body and so on.
Further, during the process of metabolism the Dhatus supporting the body,undergo twofold conversion into excretion and essence having been acted upon by the respective one of the seven Agnis.
The Agni, which digests food, is regarded as the master of all Agnis because increase and decrease of other Agnis depend on the digestive fire. Hence one should maintain it carefully by consuming properly the wholesome fuel of food and drinks because on its maintenance depends the maintenance of life-span and strength. One who eats greedily, leaving aside all the rules, soon, acquires the disorders due to morbidity in grahani (intestines).
How Agni (fire) is deranged?
Agni is deranged by fasting, eating during indigestion, over-eating, irregular eating, and intake of unsuitable, heavy, cold, too rough and contaminated food, faulty administration of emesis, purgation and unction, emaciation due to some disease, faulty adaptation to place, time and seasons and suppression of natural urges. Agni thus deranged becomes unable to digest even the lightest of food and the undigested food becomes acidified and toxic.
Indigestion exhibits the following symptoms :- stasis of food, malaise, headache, fainting, giddiness, stiffness in back and waist, yawning, body ache, thirst, fever, vomiting, griping, anorexia and improper digestion of food. Severe food toxins when combined with Pitta produce burning sensation, thirst, and disorder of mouth, acid gastritis and other paittika disorders. When combined with Kapha it gives rise to phthisis, coryza. prameha and other Kapha’s disorders. It produces various vatika disorders if combined with vata affecting urine, faeces and Rasa etc. (Dhatus). It causes disorders of urine, belly and dhatus respectively.
Digestive fire, if irregular causes disequilibrium in dhatus because of irregular digestion (of nutrients) and if intense having little fuel, dries up the dhatus.
The normal digestive fire in a person taking proper food maintains the equilibrium of dhatus by regular digestion.
The weak digestive fire burns the food incompletely, which goes either upwards or downwards. When it moves downwards either in ripe or unripe condition, it is known as the disorder of grahani (intestines). In such patients, often the entire food is half burnt or the stool is frequent, constipated or liquid. There is, presence of thirst, anorexia, abnormal taste in mouth, excessive, salivation and feeling of darkness. Besides, oedema of feet and hands, pain in body joints, vomiting and fever are there. Eructation havemetallic or fleshy odor and bitter sour taste.
Prodromal symptoms are the following: thirst, lassitude, and debility, burning of food, delayed digestion and heaviness of body.
Grahani is the scat of Agni (fire) and is called so because it hold the food. It is situated above umbilicus, and is strengthened by the power of Agni. Normally, it holds up the food (till it is digested) and releases it from the side after it is digested but when it is deranged due to weak digestive fire it releases the ingested material even in an unripe condition.