Ritu, the season, classified by different features expresses different effects on the body as well as the environment. Ayurveda has depicted various rules and regimens (Charya), regarding diet and behavior to acclimatize seasonal enforcement easily without altering body homeostasis. The prime principle of Ayurvedic system of medicine is preventive aspect, can be achieved by the change in diet and practices in response to change in climatic condition. This is a very important aspect of preventive medicine as mentioned in Ayurvedic texts. Lifestyle disorders are very common in the present era, basically originating from lack of following seasonal regimens due to lack of concentration in seasonal characteristics.
Ayurveda, the age old science of life, has always emphasized to maintain the health and prevent the diseases by following proper diet and lifestyle regimen rather than treatment and cure of the diseases. The basic principle followed in the Ayurvedic system of medicine is Swaasthyashya Swaasthya Rakshanam, which means to maintain the health of the healthy, rather than Aturashya Vikara Prashamanancha, means to cure the diseases of the diseased.
For this purpose the Dinacharya (daily regimen) and Ritucharya(seasonal regimen) have been mentioned in the classics of Ayurveda.
With the change in season, the change is very evident in the environment we live in. We see various changes in bio-life around us, such as flowering in spring and leaf-shedding in autumn in the plants, hibernation of many animals with the coming of winter, and so on. As human being is also part of the same ecology, the body is greatly influenced by external environment. Many of the exogenous and endogenous rhythm have specific phase relationship with each other; which means that they interact and synchronize each other. If body is unable to adopt itself to stressors due to changes in specific traits of seasons, it may lead to Dosha Vaishamya, which in turn may render the body highly susceptible to one or other kinds of disorders.
As adaptations according to the changes, is the key for survival , the knowledge of Ritucharya (regimen for various seasons) is thus important. People do not know or ignore the suitable types of food stuffs, dressing, and others regimen to be followed in particular season, this leads to derangement of homeostasis and causes various diseases, such as obesity, diabetes, hypertension, cancer, and so on. Lifestyle diseases are a result of an inappropriate relationship of people with their environment.
Ritucharya is prominently discussed in the first few chapters of most of the Samhitas of Ayurveda. Prevention of disease to maintain health is being the first and foremost aim of the holistic science of Ayurveda. In Tasyashitya chapter of Charaka Samhita, it is said “Tasya Shitadiya Ahaarbalam Varnascha Vardhate. Tasyartusatmayam Vaditam Chestaharvyapasrayam,” which means ‘the strength and complexion of the person knowing the suitable diet and regimen for every season and practicing accordingly are enhanced.
The year according to Ayurveda is divided into two periods Ayana (solstice) depending on the direction of movement of sun that is Uttarayana (northern solstice) and Dakshinayana (southern solstice). Each is formed of three Ritus (seasons). The word Ritu means “to go.” It is the form in which the nature expresses itself in a sequence in particular and specific in present forms in short, the seasons.
A year consists of six seasons, namely, Shishira (winter), Vasanta (spring), and Grishma (summer) in Uttarayan and Varsha (monsoon), Sharata (autumn), and Hemanta (late autumn) in Dakshinayana. As Ayurveda has its origin in India, the above seasonal changes are observed predominantly in Indian subcontinent.
Keeping all the health factors and wellbeing into consideration one has to follow ritucharya.