Ayurveda describes the existence of three fundamental types of human metabolisms, and these are known as “dosas” (pronounced, and sometimes spelled ‘doshas’) and – in a very general, vague and partial way - roughly analogous to the western medical concepts of endomorphic, mesomorphic and ectomorphic body types.
The Sanskrit word “dosa” means fault, or stain. More generally, it means “mark” – that which characterizes what it is impressed upon. A related word is “dushya,” which means that which is affected – or stained – by the dosas. In other words, the “dosa” is the energy that is contained, and the “dushya” is it’s material (tissue, organ) container.
These “dosas” are known collectively as the Tridosa, (tridosa = three dosas) or “three categories,” and include the Kapha, Pitta and Vata. Regimens for maintaining health and for its restoration vary from one type to the next. Not only do the dosas reflect categories of metabolisms, but they are also energies by which an otherwise inert body is rendered animate. The chemical energies of life may coexist intimately, but – absent the energizing action of the tridosa – they remain inert, dead, and a mere collection of substances. Each of the dosas is said to be represented by one or more of the four elements of the classical world: fire, earth, air or water, thus, in order of increasing density or grossness:
All of the three dosas coexist in each organism from the bodily down to the cellular levels; rarely does one predominate exclusively. Rather, an organism may present a mixture of two or even three types, with one predominating. All three dosas have a very strong motivation – at the cellular level – to balance, coordinate and function harmoniously.
Such imbalances of the dosas as invariably give rise to disease begin generally at the cellular level. Apart from the results of physical injury or chemical insult, an imbalance of the dosas is – without exception – the origin of all disease processes.
How is it that the dosas – which as forms of energy are not composed of any material substance – are said to relate to the material elements? Simply put, the relationship is one of correspondence, not composition. They share properties, and in this they resemble each other. Thus, in its properties, Vata is “like” space (ether) and air, Pitta is “like” fire and water, and Kapha is “like” water and earth.
Similarly, the dosas can be said to correspond with the gunas because they “resemble” them and behave similarly: thus, Vata is “like” Sattva,” Pitta is “like” Rajas and Kapha is “like” Tamas.
The dosas do not have structures. They cannot be analyzed or measured. Nonetheless, even a casual observer cannot but agree that they exist as described in the literature of Ayurveda, such descriptions being the result of accumulated millennia of clinical observation.