Health is defined in Ayurveda as the soundness of body (sharira), mind (manas) and soul (atma). Each part of this tripod of life should receive equal attention as psychic influences strongly affect the body in health as well as in disease, a fact that is only recently being acknowledged in modern medical science. Modern medicine takes pride in its understanding of physiology thus emphasizing fragmentation, isolation and disunity in its study of human system, while according to Ayurveda, disease is seen as the result of disruption of the spontaneous flow of nature’s intelligence within the physiology. Ayurvedic definition of health or svasthya provides a good illustration of the holistic nature of the knowledge system. It implies equilibrium of body tissues, physiological functions, excretory processes, the senses and the mind.

While western health sciences look to the physical body for their data, studying them as isolated parts, Ayurvedic medicine views the human body as groups of interrelated and interdependent structures and functions governed basically by three biological elements or biophysiological factors. These are the Tridoshas.

In perfect balance in the body Vata, Pitta and Kapha are the Tridhatus or the three root governing principles. Dhatu is derived from Sanskrit ‘Dha’ meaning that which nourishes and supports. Dhatus essentially sustain and nourish the body. In all living things – animals or plants – these constitute the basic functional units and are subject to influences both within and without. Within the constitutional limits of disease-free state, dhatus are not taken away from equilibrium enough to cause or trigger causative factors leading to disease. Since in their disequilibrium lies the root cause of all disease, they are called Tridoshas (dosha literally meaning a blemish).

Arogya (absence of disease) is the result of a balanced state of the doshas each of which has a specific pramana (quantity), guna (quality) and karma (action) in the body. Food habits and environmental factors that are contrary to the qualities of a particular dosha bring about its increase (vriddhi) or decrease (ksaya). Though both of these are considered abnormal (vikruta), it is the increase that causes major disturbances, while decrease typically causes only minor disturbances.

Vata, Pitta and Kapha correspond to Vayu, Tejas and Ap of the Panchamahabhootas. This is because prithvi and akash have no definite actions of their own and are not the direct cause of any disease. They function in association with the other three elements in the body. The terms vata, pitta and kapha (or sleshma) are derived respectively from the Sanskrit roots ‘Va’ meaning to move or to excite, ‘Tap’, to heat and ‘Slis’, to hold together. A right conception of these factors is the basis for a right understanding of the essence of Ayurveda.