Ayurveda (Sanskrit: आयुर्वेद), "the knowledge for long life" or ayurvedic medicine is a system of traditional medicine native to India and a form of alternative medicine to the modern form medicines and vaccines. The earliest literature on Indian medical practice appeared during the Vedic period in India, i.e. in the mid-second millennium BCE. The Suśruta Saṃhitā and the Charaka Saṃhitā, encyclopedias of medicine compiled from various sources from the mid-first millennium BCE to about 500 CE, are among the foundational works of Ayurveda. Over the following centuries, ayurvedic practitioners developed a number of medicinal preparations and surgical procedures for the treatment of various ailments. Current practices derived (or reportedly derived) from Ayurvedic medicine are regarded as part of complementary and alternative medicine.
At an early period, Ayurveda adopted the physics of the "five elements" namely Devanāgarī: [महा] पञ्चभूत, Prithvi (earth), Jala(water), Agni (fire), Vayu (air) and Akasa (sky) — that compose the universe, including the human body. Chyle or plasma (called rasa dhātu), blood (rakta dhātu), flesh (māṃsa dhātu), fat (medha dhātu), bone (asthi dhātu), marrow (majja dhātu), and semen or female reproductive tissue (śukra dhātu) are held to be the seven primary constituent elements – saptadhātu (Devanāgarī: सप्तधातु) of the body. Ayurvedic literature deals elaborately with measures of healthful living during the entire span of life and its various phases. Ayurveda stresses a balance of three elemental energies or humors: Vāyu vāta (air & space – "wind"), pitta (fire & water – "bile") and kapha (water & earth – "phlegm"). According to ayurvedic medical theory, these three substances — dosas (literally that which deteriorates – Devanāgarī: दोष)—are important for health, because when they exist in equal quantities, the body will be healthy, and when they are not in equal amounts, the body will be unhealthy in various ways. One ayurvedic theory asserts that each human possesses a unique combination of doṣas that define that person's temperament and characteristics.
Another view, also present in the ancient literature, asserts that humoral equality is identical to health, and that persons with preponderances of humours are proportionately unhealthy, and that this is not their natural temperament. In ayurveda, unlike the Sāṅkhya philosophical system, there are 20 fundamental qualities, guna (Devanāgarī: गुण, meaning qualities) inherent in all substances. Surgery and surgical instruments were employed from a very early period, Ayurvedic theory asserts that building a healthy metabolic system, attaining good digestion, and proper excretion leads to vitality. Ayurveda also focuses on exercise, yoga, and meditation.