Tridosha is the conceptual framework upon which Ayurveda is based.  The doshas are dynamic qualities within an individual.  Health exists when the doshas function harmoniously with each other.  Disease occurs when one or more of these doshas become imbalanced.  The doshas are a metaphoric framework cutting across most western categories of thought.  The three doshas are (see table 1): 

Kapha

Pitta

Vata

Though associated with mucous secretions, bilious secretions and nerve currents, it is important to stress that these are actually universal terms.  All things:  foods, activities and conditions may be categorized in this system. 

Rarely are the humoral activities balanced within an individual; humans have a tendency to over-produce activity in one or more doshas.  In fact, everyone may be categorized as being Kappha, Pitta or Vata predominant.  If these excesses accumulate and are not eliminated, the body is made vulnerable to toxins and harmful bacteria.  According to Ayurvedic theory, a body free of harmful bacteria, toxins and tridosha imbalance will not succumb to sickness.  Dosha excesses can accumulate in any constitution due to poor diet and unhealthy living habits.  It is relatively easy to rid oneself of excesses which are different from the individual’s predominant dosha.  For example, excess mucous (kapha excess) in a fire-predominant (pitta) person would be easily burned off.  On the other hand, if the pitta predominant person contracted jaundice, an excessive bilious (pitta) condition, it would be difficult to cure because his/her constitution would complicate the disease instead of counteracting it.  It follows that diseases of the digestive system are most difficult to cure for Pitta, diseases of the nervous system for Vata and diseases of the lymph and respiratory system for Kapha.

The first concern of the Ayurvedic physician is to eliminate excesses of the predominant dosha and second to strengthen and normalize tridosha balance.  First, s/he must determine the predominant dosha in the client’s constitution and then prescribe a diet and general living regimen including yoga asanas and breathing excercises suited to the individual’s body and temperament.  The client should avoid all foods, activities and conditions which excite his/her already overactive dosha while acting to stimulate the balancing activities of the latent doshas.