Charaka was one of the principal contributors to the art and science of Ayurveda, a system of medicine and lifestyle developed in Ancient India. He is sometimes dated to 800 BC as he worked on the older treatise by Purnvasu Atreya (1000 BC) and Agnivesa, whose work, the Agnivesha Tantra, was the basis of his Charaka Samhita. Charaka is also referred to as the Father of Medicine. He was a native of Kashmir.
Charaka was the first physician to present the concept of digestion, metabolism and immunity. According to his translation of the Vedas, a body functions because it contains three doshas or principles, namely movement (vata), transformation (pitta) and lubrication & stability (kapha). The doshas are also sometimes called humours, namely, bile, phlegm and wind. These doshas are produced when dhatus (blood, flesh and marrow) act upon the food eaten. For the same quantity and quality of food eaten, one body, however, produces doshas in an amount different from another body. That is why one body is different from another.
Charaka studied the anatomy of the human body and its various organs. He is the author of Charaka Samhita, which has survived and has been handed down to us in the form of Bower Manuscript dated to around 4th century. Charaka Samhita is one of the two foundational texts of Ayurveda. Charaka Samhita contains 120 adhyayas (chapters), and is divided into 8 parts. It has a total of 12000 shlokas and description of 2,000 medicines.