Dhanvantari is an Avatar

Avatar

In Hinduism, an avatar is a deliberate descent of a deity to earth, or a descent of the Supreme Being and is mostly translated into English as "incarnation," but more accurately as "appearance" or "manifestation"....

 of Vishnu

Vishnu

Vishnu is the Supreme god in the Vaishnavite tradition of Hinduism. Smarta followers of Adi Shankara, among others, venerate Vishnu as one of the five primary forms of God....

 from the Hindu

Hindu

Hindu refers to an identity associated with the philosophical, religious and cultural systems that are indigenous to the Indian subcontinent. As used in the Constitution of India, the word "Hindu" is also attributed to all persons professing any Indian religion...

 tradition. He appears in the Vedas

Vedas

The Vedas are a large body of texts originating in ancient India. Composed in Vedic Sanskrit, the texts constitute the oldest layer of Sanskrit literature and the oldest scriptures of Hinduism....

 and Puranas

Puranas

The Puranas are a genre of important Hindu, Jain and Buddhist religious texts, notably consisting of narratives of the history of the universe from creation to destruction, genealogies of kings, heroes, sages, and demigods, and descriptions of Hindu cosmology, philosophy, and geography.Puranas...

 as the physician of the gods (devas

Deva (Hinduism)

' is the Sanskrit word for god or deity, its related feminine term is devi. In modern Hinduism, it can be loosely interpreted as any benevolent supernatural beings. The devs in Hinduism, also called Suras, are often juxtaposed to the Asuras, their half brothers. Devs are also the maintainers of...

), and the god of Ayurvedic

Ayurveda

Ayurveda or ayurvedic medicine is a system of traditional medicine native to India and a form of alternative medicine. In Sanskrit, words , meaning "longevity", and , meaning "knowledge" or "science". The earliest literature on Indian medical practice appeared during the Vedic period in India,...

 medicine. It is common practice in Hinduism for worshipers to pray to Dhanvantari seeking his blessings for sound health for themselves and/or others.
Sri Dhanvantari is the primordial God (Avatar) of health care. As such, persons have taken the name "Dhanvantari" in connection with their attempts at medical interventions.