Ayurveda, also known as Ayurvedic medicine is a Hindu system of traditional medicine native to India. This alternative form of healing is based upon three constitutions: Vata (air), Pitta (fire) and Kapha (earth). The earliest literature on Indian medical practices first appeared during the Vedic period in India during the mid-second millennium BCE. The foundational works of Ayurveda were compiled from the Susruta Samhita and the Charaka Samhita encyclopedias of medicine, compiled from various sources during the mid-first millennium BCE to about 500 CE. Over the following centuries, Ayurvedic practitioners developed a number of medicinal preparations and surgical procedures for the treatment of various ailments. Current practices derived from Ayurvedic medicine are regarded as part of complementary and alternative medicine. Meditation, yoga and the alkaline diet stem from this 7,000 year old science.