Causation of Diseases
The imbalance of the doshas in the body are the result of disharmony between the man and the outer world (purusha and loka).
Changes in the external environment can happen in the following ways:
1. Improper use of the senses (Asat-myendriyartha samyoga).
2. Thinking, speaking and acting incorrectly in spite of knowing better. (Prajnaparadha).
3. Extreme climatic variations (Rtu Parinama)
The body reacts to these stimuli or changes by rebalancing the tridoshas, leading to a state of equilibrium, resulting in good health. The cognitive organs (jnanendriyas) generally work within narrow limits against the variations in the external environment. When these variations are within normal limits, the balance of doshas is maintained.However, when any of the following occur, an over-stressing (atiyoga), under stressing (hinayoga), no stress (ayoga), or improper stress (mithyayoga), with the sense organs, they exert an internal stress in the body which leads in each case to the overall imbalance of the tridoshas’ equilibrium. Recovery from these internal stresses and the survival of the individual are mostly determined by the ability of the tridoshas to attain a state of equilibrium (samyata of doshas). The time interval between the deterred balance of doshas (dosha vaishamya) and restoration of a state of equilibrium (dosha samyata) constitute the various stages of the disease process which are explained as kriyakalas or the stages of the disease at which the treatment should be done.
According to Sushruta samhita, there are six stages or kriyakalas:
1. Samchaya, (Accumulation)
2. Prakopa, (Aggravation)
3. Prasara, (Leave and spread)
4. Sthanasamshraya (Augumentation/Presymptoms)
5.Vyakti (Symptoms/Something can be seen)
6. Bheda (Differentiation/Disease Formation/Stage of complications)
A thorough knowledge of the concept of kriyakalas is needed for the recognition of the disease process even in its very beginning stage. Sushrutahas re-marked that ‘‘Only he, who knows properly sancha-ya, prakopa, prasara, sthanasamshraya, vyakti, and thebhedastages of doshas can be regarded as areal physician.’’