Tridosha is the three defects arising from the derangement of the three humors – vata (wind), pitta (bile) and kapha (phlegm) in the body denoted in the ancient Hindu system of medicine (Ayurveda). The three humors are related to the three qualities sattva, rajas and tamas, referred to as mahagunas by the medical writer Vaghbhata. They have their respective jurisdiction below the navel, the middle region above the navel and up to the neck and the head.
In general, the three qualities sattva, rajas and tamas are characterized by the three humors – bile, wind and phlegm. According to the medical authority Sushruta, the three humors are the cause for the origin of the body. Some authorities add the blood also. The whole edifice of the system of the Indian medicine is based on the imbalance of the three humors. It is stated that the normal functioning of the body rests on the equilibrium of these three humors.
The imbalance of the humors gives rise to the vitiation of the vital energy and indisposition. Although only a practitioner of Yoga can maintain their equilibrium, it is not impossible for an ordinary person to maintain near equilibrium. If one humor is disturbed, it affects the other two and gives rise to indisposition relating to the predominant humor. In the same way as the mental feeling of a person is exhibited in his actions, the food we take produces the corresponding effect in the body, enabling us to infer the preponderance or vitiation of a particular humor.