The Agni is chiefly situated in Jatara or the upper part of the digestive system and this Agni is known as Jataragni. The Agni is further classified into Bhootagni (which digests the 5 pancha mahabhoota factors present in food), Dhatwagni (The Agni present in tissues which help them to absorb required nutrients), Malagni (the Agni which helps in formation of body wastes like stools, sweat and urine).
Samagni is the condition when the Agni is present in appropriate composition and carries out its respective functions properly. Agni initiates digestive activities in the digestive tract and generates thoughts, emotions and decisions in our mind. The heat of Agni helps in the digestion of external elements that enter our body. The food which enters our digestive tract is converted into life sap which ensures our survival, growth and recuperation from illness. The knowledge of the external environment which enters our body through our special senses is transformed into memories with the help of agni which further initiates thoughts, generates emotions and helps in taking decisions.
Agni also helps in destroying toxins that are produced if there is an imbalance of doshas. In other words agni helps in maintaining the status of health and in interrupting the disease process. In the Samagni condition, the immune system of our body is perfectly maintained and saves us from the attack of internal and external trespassers. Agni keeps a careful watch on the body functions. Samagni ensures that the food is completely digested by all the Agnis, so that the body tissues are well nourished and one is blessed with attractive complexion, glow, longevity, strength, good health, growth, enthusiasm, vivacity and overall healthy development of the body and the mind.
The factors which help Agni to digest the food completely and to maintain the Samagni condition are the tridoshas - Vata , Pitta and Kapha. When all these factors are normal and well balanced, an optimum condition is created to digest the food completely. Indigestion occurs when Agni is imbalanced by any disruption in the composition of the doshas. There are three types of variations from the Samagni condition which indicate that the body is not healthy. When vata is predominant we experience Vishamaagni or varying Agni. The regular food gets digested normally on a few occasions and poorly on others. Foods and lifestyles that increase vata lead to this condition. This variation of Agni causes constipation, flatulence, pain in the abdomen and other vata predominant diseases.
Teekshnagni or increased Agni occurs due to predominance of pitta. Pitta increasing foods and lifestyle cause this variation. This variation of Agni causes increased hunger, thirst, acidity, heart burn and loose motions. Mandagni or decreased Agni is a condition where increased wetness or kapha reduces the intensity of the body fire. Foods and lifestyle that aggravate kapha cause this variation. A feeling of heaviness in the body, the swelling of the lower eyelids, belching that emit the stench of food consumed and water brash are a few symptoms of indigestion caused by mandagni. The decreased Agni inappropriately digests the food and this indigested food is sticky in nature and improperly nourishes the tissues, causing weakness of the body. This sticky improperly digested food, known an ama, blocks the channels of the body, causes imbalance in the doshas , contaminates the tissues, hampers the body functions and cause diseases.
When the body loses the balance of Agni, it immediately needs to recover the Samagni condition. This can be achieved through various therapeutic treatments. Fasting completely for one day helps to regain the bodily balance. Other ways for recovering Samagni include consumption of liquid foods, boiled vegetables or fruit juices for a few days. Moreover there is abdominal massage that relaxes the tight muscles and increases the blood supply to the digestive system.
In conclusion, we can say that Samagni is essential for preserving the healthy condition of the body and mind. It is maintained through the consumption of well- balanced food which also keeps the doshas in a balanced condition. When this balance of the bodily fire is disturbed, the body becomes prone to ailments. Asthanga Ayurveda suggests therapeutic procedures to regain bodily health.