Introduction
Dhanvantari is the physician of the gods and, in Puranic and Ayurvedic tradition, the divine source of the science of medicine (Ayurveda). He is best known for emerging from the churning of the ocean of milk carrying the pot of amrita, the nectar of immortality.
This article follows the Puranic tradition. Where a detail differs between texts, the article says so.
The churning of the ocean
Among the treasures that rose from the churning of the ocean of milk (Samudra Manthan), Dhanvantari appeared last, bearing a golden pot of amrita, which touched off the contest between the gods and demons for its possession, ultimately resolved by Vishnu as Mohini.
Founder of Ayurveda
Dhanvantari is regarded as an avatar of Vishnu, and is credited in the Ayurvedic tradition, particularly in texts associated with the Sushruta Samhita, as the source from whom the science of medicine and surgery was transmitted to human physicians. He is invoked at the start of Ayurvedic study and practice.
Worship
Dhanteras, the first day of the Diwali festival period, is dedicated to Dhanvantari (as well as to prosperity more generally, from which the day takes its association with buying gold and utensils), and National Ayurveda Day in India is observed on this date. He is shown with four arms, holding a pot of amrita, a leech (for treatment), a conch and a discus.