Ayurveda or Ayurveda medicine, is a system of medicine with historical roots in the Indian subcontinent. Globalised and modernised practices derived from Ayurvedic traditions are a type of complementary or alternative medicine. In countries beyond India, Ayurveda therapies and practices have been integrated into general wellness applications and in some cases in medical use.
The main classical texts of Ayurveda begin with stories of the transmission of the medical knowledge of the gods to the wise, and then to the human doctors. In Sushruta Samhita (Compendium of Sushruta), Sushruta wrote that Dhanvantari, Hindu god of Ayurveda, incarnated like king of Varanasi and taught medicine to a group of doctors, including Sushruta. Ayurveda therapies have varied and evolved for over two millennia. Therapies are often based on complex compounds of herbs, minerals and metallic substances (perhaps under the influence of alchemy or rasa shastra). The ancient texts of Ayurveda also taught surgical techniques, including rhinoplasty, extractions of kidney stones, sutures and extraction of foreign objects.
Although laboratory experiments suggest that it is possible that some substances used in Ayurveda can be developed in effective treatments, there is no evidence that none are effective as is currently practiced. Ayurvedic medicine is considered pseudo-scientific. Other researchers consider it a protoscience, or trans-science system instead. In a 2008 study, about 21% of Ayurveda USA and patent medicines manufactured by India sold over the Internet were found to contain toxic levels of heavy metals, specifically lead, mercury and arsenic. The public health implications of such metal contaminants in India are unknown.
Some scholars claim that Ayurveda originated in prehistoric times, and that some of the concepts of Ayurveda have existed since the time of the Indus Valley Civilization or even earlier. Ayurveda developed significantly during the Vedic period and later some of the non-Vedic systems like Buddhism and Jainism also developed concepts and medical practices that appear in the classic texts of Ayurveda. Emphasis is placed on humoral balance, and the suppression of natural impulses is considered unhealthy and is claimed to lead to disease. The Ayurvedic treatises describe three elemental substances, humors (Sanskrit doṣas), wind (Sanskrit vāta), bile (pitta) and phlegm (kapha)), and claim that equality (Skt. Sāmyatva) health, while viṣamatva inequality) produces disease. The treatises of Ayurveda divide the medicine into eight canonical components. Ayurveda practitioners had developed various medicinal preparations and surgical procedures since at least the beginning of the common era.