As the natural and Geographic location of Indian subcontinent being of a peculiar type, changes in the atmosphere based on appropriate time is noticed and based on this six, Rhutus (seasons) can be observed. The change in the atmosphere has a definitive bearing on the health of the humans and hence one can see people suffering from different diseases in different Rhutus.

According to the Rhutus the status of the Tridosha – Vata, Pitta and Kapha also changes. In accordance with the atmosphere, the changes in the stages of Dosha – Chaya (accumulation), Prakopa (aggravation) and Prasham (alleviation) that come about are natural. To expect the Prokopavastha (stage of aggravation), to be followed by Prashamavastha (stage of alleviation), i.e. for them to get calm is expected. But if in this stage improper dietary or behavioural pattern is followed then the Prakupit (aggravated) Doshas do not attain the normal Prashamavastha (stage of alleviation), but instead enter into Prasravastha (stage of spreading). These aggravated Doshas then spread into entire body through the channels known as Srotas and get themselves lodged (Sthansanshraya) at pre-vitiated places.