The origin of Ayurveda dates back to the Vedic era. Most material relating to the health and diseases are available in Atharva veda. Historians claim that Ayurveda is a part of Atharva Veda. However RigVeda which is the earliest Veda also mentions about diseases and medicinal plants. In Athrava veda there are hyms which mention about medicines like Accorus calamus and Phylanthus Embelia. The systematized form of Ayurveda dates back to the prehistoric period of Rishi Conference which was held in the foot hills of Mount Himalaya. The earliest codified document on Ayurveda is Charaka Samhita. Sushruta samhita is another codified document. Sushruta tradition was said to be descended and propagated by Dhanvantari whereas Charaka tradition was descended through Atreya. Sushruta School is dominated by surgical procedures and techniques while Charaka Samhita deals with internal medicine.
Charaka Samhita also mentions the names of the earliest disciples of Atreya as Agnivesh, Bhela, Jatukarna, Parashar, Harita and Ksharpani and they separately created their own treaties in the field of internal medicine. Out of these six, Charaka Samhita and Bhela Samhita are available in authentic form today, however, Harita Samhita which is also available, but its authenticity is questionable. Many of the manuscripts were lost due to foreign invasions which resulted in big setback to this ancient knowledge of life.