Charaka was said to have been in the court of the Kushana king, Kanishka during the 1st century A. D. Some authors date him as far back as the 6th century B.C. during Buddha period. The sacred trust between physician and patient was held in high esteem by Charaka and patient confidentiality, similar to the Hippocratic Oath, was deemed the proper conduct for a practicing physician. Charaka also told us that the word Ayurveda was derived from Ayus, meaning life and Veda. Nevertheless, according to Charaka the word Ayus connotes more than just life. Ayus denotes a combination of the body, sense organs, mind and soul. The principles of treatment in Charaka's teachings took a holistic approach that treated not just the symptoms of the disease but the body, mind and soul as single entity.
Compiled by Charaka in the form of discussions and symposiums held by many scholars, Charaka Samhita is the most ancient and authoritative text that has survived. Written in Sanskrit in verse form, it has 8400 metrical verses. Following the Atreya School of Physicians, the Samhita deals mainly with the diagnosis and treatment of disease process through internal and external application of medicine. Called Kaya-chikitsa (internal medicine), it aims at treating both the body and the spirit and to strike a balance between the two. Following diagnosis, a series of methods to purify both the body and spirit with purgation and detoxification, blood letting and emesis as well as enema (known as Pancha-karma) are utilized. The emphasis seems to be to tackle diseases in the early phase or in a preventative manner before the first symptoms appear.
Ayurvedic diagnosis and treatment is traditionally divided into eight branches (sthanas) based on the approach of a physician towards a disease process. Charaka described them thus:
1. sutra-sthana, general principles
2. nidana-sthana, pathology
3. vimana-sthana, diagnostics
4. sharira-sthana, physiology and anatomy
5. indriya-sthana, prognosis
6. chikitsa-sthana, therapeutics
7. kalpa-sthana, pharmaceutics
8. siddhi-sthana, successful treatment.
Detailed accounts of various methods of diagnosis, study of various stages of symptoms and the comprehensive management of debilitating diseases like diabetes mellitus, tuberculosis, asthma and arthritic conditions are to be found in the Charaka Samhita. There is even a detailed account of fetal development in t