All the physical manifestations in the universe are made up of five basic elements or building blocks, which represent the corresponding subtle energies, which are also known as Tatvas. Bhut implies the eternal energy that can take any form. Thus, Panchtatvas or Panchmahabhutas are the five basic elements that operate in various combinations resulting in the creation, maintenance and destruction observed in nature. These elements are Akashtatva (space), Vayutatva (air), Agnitatva (fire), Jaltatva (water) and Pruthvitatva (earth).
The changes taking place in all animate and inanimate forms, including humans, are a result of the transformation in the elements. Such changes in the environment also manifest in the human body and mind. For instance, the fire element in the body increases as the day progresses, while simultaneously the water element reduces. This means that Jaltatva gets converted into Agnitatva. On the mental plain, inflammatory thoughts represent fire, while unstable thoughts represent air. Similarly, sensitive thoughts denote water element, while self-confidence denotes earth element. A peaceful temperament indicates space element. Any imbalance in the five elements due to any reason leads to disease.
The solid and hard aspects in the world of nature are primarily made up of this element. The same applies to human body. All hard parts of the body such as bones, joints, ligaments, hair, teeth, cartilages, outer layer of cells, hollow organs, outer layer of veins and arteries, nerves, etc. are primarily made up of Pruthvitatva. This element plays a major role in the formation of muscles, fat, spinal cord and semen. It provides strength and continuity to all the hard formations, skeleton and physical support structure in the body. Ingestion and excretion ensures the balancing of earth element in the body.
The bodily energy store in the form of Ojas manifests in the form of Kaph, which is derived from water and earth elements. This provides the basic nutrition to the body. Water is the protective element in the body. It protects the body from depletion in the Akashtatva, turbulence and speed in the Vayutatva and heat of the Agnitatva. Any kind of inflammation, burning sensation or pain is pacified by Jaltatva. There are five types of Kaph (Jal + Pruthvi) in the body.
Avalambak Kaph: This Kaph resides in the chest and keeps the entire respiratory system moist and lubricated.
Kledak Kaph: This Kaph moistens the hard or heavy food stuff that reaches the stomach. It also aids in digestion by protecting the slimy lining of the stomach from acids.
Bodhak Kaph: This Kaph is the saliva and aids in knowing the taste and in digestion.
Tarpak Kaph: This Kaph is located in the head and nurtures the organs of perception and protects the nerves in the brain.
Shleshak Kaph: This Kaph located in the joints provides them with lubrication and strength. It also protects the joints from friction.
Every cell in the body has Agni residing in it. Pitta in the body is formed from fire and water elements, and is the manifestation of Tejas or the internal glow. According to Ayurved, Agni is the important component involved in digestion and metabolism. Agni is responsible for all the important aspects of a person including nutrition, strength, desire, skin tone, will to live, health, Ojas, Tejas and Pran (life sustaining energy).
Rushi Charak had mentioned that when the Agni in the body is in equilibrium, then the person lives a healthy, long and happy life. If it gets into imbalance, diseases occur. When the function of Agni completely ceases, a person dies. He had described 13 types of Agni in the human body. They include the Jatharagni, seven types of Dhatvagni and five types of Bhutagni.
Jatharagni: It is located in the stomach and lower gut and it enables the digestion of the food ingested and metabolism.
Dhatvagni: Food digested by Jatharagni is transformed into the substance of the various Dhatus (important components of the body structure). Dhatvagni converts that into the seven Dhatus (Ras, Rakt, Mams, Med, Asthi, Majja and Shukra).
Bhutagni: This Agni also described as Bhaumagni / Parthivagni, Apyagni, Agnyagni, Vayavyagni and Nabhasagni, further converts the food transformed into Saptdhatus and Panchmahabhutas.
The life sustaining energy or Pran, manifesting as Vaat, is derived from air and space elements. Transporting is the main function of Vayu. When it flows freely through the Nadis, it provides nutrition, energy, motility and comprehensive health to all parts including muscles, nerves, cells and other organs. There are five types of Pranas (Vayu + Akash) in the body.
Pran: This is the flow of energy active in the region of the chest. It enables the functioning of the heart and lungs.
Apan: This flow of energy is active below the navel in the region of the lower abdomen. It provides energy to the large intestine, kidney, anus and reproductive organs.
Saman: This energy flow is active in the region between the heart and navel. It energizes the liver, intestines, pancreas and stomach.
Udan: This flow of energy is active in the region of the head and mind. It activates the sense organs of eyes, tongue, nose and ears.
Vyan: This energy flow pervades the entire body. Its main functions are regulating the movements of the body, and coordinating with other Pranas and strengthening them.
This is the all pervading space element. It permeates everything and is boundless. Space is steady because it does not have the restlessness associated with Vayu. It is cold since it does not have the heat of Agni, and is light because it is devoid of the weight of Jal and Pruthvi. However, since other elements emerge from Akashtatva, it is the basis of them all. The other Tatvas are present in Akash in dormant form.