The central concept of Ayurvedic medicine is the theory that health exists when there is a balance between three fundamental bodily humours or doshas called Vata, Pitta and Kapha

All Ayurvedic physicians believe that these ancient ideas, based in the knowledge discovered by the Rishis and Munis, exist in harmony with physical reality. These Ayurvedic concepts allow physicians to examine the homeostasis of the whole system. People may be of a predominant dosha or constitution, but all doshas have the basic elements within them.

The term vata stems from a Sanskrit word "vaayu" which means “that which moves things”; it is sometimes translated as wind. It is composed of the elements space and air--the lightest and subtlest of the five elements. It is considered in some ways to be the most influential of the three doshas because it is the moving force behind the other two doshas, which are incapable of movement without it. Vata dosha is responsible for all the somatic activities and sensations.

The term pitta comes from the Sanskrit word pinj meaning “to shine” (according to Sir Monier-Williams its exact entomology is a mystery). It carries the meaning of “that which digests” and is associated with the idea of being yellow-tinged or bilious. In its widest sense, Paittika digestive function includes all chemical and metabolic transformations in the body as well as processes which promote heat production (i.e. conversion of iodine to triiodotyrosine in the thyroid gland). Pitta also governs our ability to digest ideas and impressions and to therefore perceive the true nature of reality. It stimulates the intellect and creates enthusiasm and determination.

The term kapha derives from the Sanskrit word "shlish" which means “that which holds things together; to embrace; coherent”. In fact, one of the other designations for kapha appearing in some of the older literature is shleshma.. It is the force which provides structure to everything from an individual atom or cell to the sturdy musculoskeletal frame. It gives strength, stability, and endurance--both physical and psychological--and promotes human emotions and capacities such as love, compassion, empathy, understanding, forgiveness, loyalty and patience.

Doshas are of two varieties: saririka (bodily) and manasika (psychological, of the mind).
This is often a point of great confusion in Ayurvedic circles. Let’s look at these two types of doshas more closely. The saririka doshas are Vata, Pitta, and Kapha. They are what we mean when we use the term “tridosha”. They are material in form, yet can manifest in aspects of mind as well. Generally, they are intimately connected to physical activities. The manasika doshas are Rajas, Tamas, and Sattva. These are often referred to as the three gunas, or three qualities, of the mind. Manasika doshas have reference only to the mind and mental activities.