Ayurvedic medicine has a long history of 3000 years. Like other oriental systems, such as those of Tibet and China, Ayurvedic medicine sees the body in terms of humours; of oppositions such as hot/cold, and of a close relationship between the body and the mind. Ayurveda is, above all, a holistic system, which treats all aspects of the mind and body together.
The three humours (dosas)are wind (vata), bile (pitta) and phlegm (kapha). These humours are perhaps best understood as forces that sustain life within the body, with wind in charge of motion, bile in charge of transformation (such as digestion), and phlegm a stabilising influence that lubricates and maintains bodily functions. When the humours are balanced, the body is healthy.
Ayurveda emphasises the need to keep dosas in check through practising moderation in daily life, for example, in sleep and diet. When ill heath does occur, diagnosis identifies which humours are out of balance. Treatments include forms of purification (panchakarma) such as sweating, vomiting and enemas, to remove excessive humours. Ayurvedic drugs act by protecting the body from excess humours, and counteracting the excessive humour itself.
Plant medicines are fundamental to all Asian medical systems, including Ayurveda. For example, the important Ayurvedic text, the Caraka Samhita, refers to 341 plant medicines, as compared to 177 medicines of animal origin and just 64 of mineral origin.
An Ayurvedic medicine will typically contain between 5 and 25 ingredients. Plant parts are used in various forms, including squeezed juices, decoctions and powders. Each plant used in Ayurveda is classified according to its effects on each humour.
In a development since the early Ayurvedic texts, many plants are now used as components of a yoga, a standard medicine made up of different ingredients. In the past, medicines would have been prepared specifically for a patient's condition. India now has a thriving pharmaceutical industry that manufactures Ayurvedic medicines.
Initially, the European colonisers of the Indian subcontinent were keenly interested in local medicines. Open minds, and a shortage of European drugs, led to active use of local drugs by British physicians, and government support for the training of Ayurvedic physicians. European doctors such as William Roxburgh and James Kerr were stimulated to carry out botanical research by their interest in medicinal plants. However, changes in government policy and medical attitudes led to the end of Ayurvedic teaching in government colleges in 1835. Ayurvedic medicine continued to be widely practiced, but without government support.
After independence in 1947, the new Indian government gave much greater support to Ayurvedic medicine. This support is mainly in the form of recognition rather than budget. There are over 100 training colleges, mostly privately run, and about 270,000 registered Ayurvedic practitioners in India today. As in Unani medicine, there is a tension between practitioners who favour integration with western medicine, and those who consider 'pure' or classical (suddha) Ayurveda better than modern medicine.
There is also controversy as to whether Ayurveda should be studied under the terms of western science. For example, western pharmacognosy seeks to identify the active principle(s) of a herbal medicine, while in Ayurveda it is the entire part of the plant that is important. Exactly the same issue arises in western herbal medicine.
Although the formal medical systems of South Asia - Ayurveda, Siddha and Unani - are the best known, there is also a strong tradition of folk medicine. This is village-based knowledge, passed from generation to generation by oral tradition. Folk medicine varies from location to location, although some medicinal plants are important nearly everywhere. Worldwide, folk medicine continues to be the main medical system in rural communities that cannot afford western medicines.