Ayurveda ( ; ) is an alternative medicine system with historical roots in the Indian subcontinent. It is heavily practised throughout India and Nepal, where as much as 80% of the population report using Ayurveda. Ayurveda has been adapted for Western consumption, notably by Baba Hari Dass in the 1970s and Maharishi Ayurveda in the 1980s. The theory and practice of Ayurveda are pseudoscientific, and many Ayurvedic preparations, particularly in the rasashastra tradition, contain toxic levels of lead, mercury, and arsenic. There is no evidence that cancer can be treated or cured through Ayurveda.

Ayurveda therapies have varied and evolved over more than two millennia. Therapies include herbal medicines, special diets, meditation, yoga, massage, laxatives, enemas, and medical oils. Early Ayurvedic preparations were almost entirely based on complex herbal compounds based on the materia medica of South Asia. Minerals and other metal substances began to enter the traditional pharmacopoeia more pervasively after the eleventh century, under the influence of early Indian alchemy or rasashastra. Ancient Ayurveda texts also taught surgical techniques, including rhinoplasty, lithotomy, sutures, cataract surgery, and the extraction of foreign objects.

Historical evidence for Ayurvedic terminology and concepts appear in the Buddhist Canon from the middle of the first millennium BCE onwards. The main classical Ayurveda texts are datable in their present form to the first centuries CE. Like many texts from classical antiquity, these texts begin with accounts of the transmission of medical knowledge from the gods to sages and then to human physicians. Printed editions of the Sushruta Samhita (Sushruta's Compendium), frame the work as the teachings of Dhanvantari, the Hindu deity of Ayurveda, incarnated as King Divodāsa of Varanasi, to a group of physicians, including Sushruta. The oldest manuscripts of the work, however, omit this frame, ascribing the work directly to King Divodāsa.

In Ayurveda texts, dosha balance is emphasised, and suppressing natural urges is considered unhealthy and claimed to lead to illness. Ayurveda treatises describe three elemental doshas: vāta, pitta and kapha, and state that balance (Skt. sāmyatva) of the doshas results in health, while imbalance (viṣamatva) results in disease. Ayurveda treatises divide medicine into eight canonical components. Ayurveda practitioners had developed various medicinal preparations and surgical procedures from at least the beginning of the common era.

Etymology The term āyurveda () is composed of two words, āyus, , "life" or "longevity", and veda, , "knowledge", translated as "knowledge of longevity" or "knowledge of life and longevity".

Eight components

The earliest classical Sanskrit works on Ayurveda describe medicine as being divided into eight components (Skt. aṅga). This characterization of the physician's art, "the medicine that has eight components" (), is first found in the Sanskrit epic the Mahābhārata, c. 4th century BCE. The components are: Kāyachikitsā: general medicine, medicine of the body Kaumāra-bhṛtya (Pediatrics): Discussions about prenatal and postnatal care of baby and mother; methods of conception; choosing the child's sex, intelligence, and constitution; childhood diseases; and midwifery Śalyatantra: surgical techniques and the extraction of foreign objects Śhālākyatantra: treatment of ailments affecting openings or cavities in the upper body: ears, eyes, nose, mouth, etc. Bhūtavidyā: pacification of possessing spirits, and the people whose minds are affected by such possession Agadatantra/Vishagara-vairodh Tantra (Toxicology): includes epidemics; toxins in animals, vegetables and minerals; and keys for recognizing those anomalies and their antidotes Rasāyantantra: rejuvenation and tonics for increasing lifespan, intellect and strength Vājīkaraṇatantra: aphrodisiacs; treatments for increasing the volume and viability of semen and sexual pleasure; infertility problems. Note, however, that the chapter-divisions of the major ancient encyclopedias of Ayurveda do not follow these divisions.

Principles and terminology

The central philosophical ideas of Ayurveda show parallels with Samkhya and Vaisheshika philosophies, as well as with Buddhism and Jainism. Moderation is emphasized, and suppressing natural urges is considered unhealthy and claimed to lead to illness. For example, to suppress sneezing is said to potentially give rise to shoulder pain. However, people are also cautioned to stay within the limits of reasonable balance and measure when following nature's urges. For example, emphasis is placed on moderation of food intake, sleep, and sexual intercourse.

According to Ayurveda, the human body is composed of tissues (dhatus), waste (malas), and humoral fluids (doshas). The seven dhatus are chyle (rasa), blood (rakta), muscles (māmsa), fat (meda), bone (asthi), marrow (majja), and semen (shukra). Like the medicine of classical antiquity, the classic treatises of Ayurveda divided bodily substances into five classical elements (panchamahabhuta) viz. earth, water, fire, air and ether. There are also twenty gunas (qualities or characteristics) which are considered to be inherent in all matter. These are organized in ten pairs: heavy/light, cold/hot, unctuous/dry, dull/sharp, stable/mobile, soft/hard, non-slimy/slimy, smooth/coarse, minute/gross, and viscous/liquid., citing Sushrutasamhita 25.36.

The three postulated elemental bodily humours, the doshas or tridosha, are vata (air, which some modern authors equate with the nervous system), pitta (bile, fire, equated by some with enzymes), and kapha (phlegm, or earth and water, equated by some with mucus). Contemporary critics assert that doshas are not real, but are a fictional concept. The humours (doshas) may also affect mental health. Each dosha has particular attributes and roles within the body and mind; the natural predominance of one or more doshas thus explains a person's physical constitution (prakriti) and personality. Ayurvedic tradition holds that imbalance among the bodily and mental doshas is a major etiologic component of disease. One Ayurvedic view is that the doshas are balanced when they are equal to each other, while another view is that each human possesses a unique combination of the doshas which define this person's temperament and characteristics. In either case, it says that each person should modulate their behavior or environment to increase or decrease the doshas and maintain their natural state. Practitioners of Ayurveda must determine an individual's bodily and mental dosha makeup, as certain prakriti are said to predispose one to particular diseases. For example, a person who is thin, shy, excitable, has a pronounced Adam's apple, and enjoys esoteric knowledge is likely vata prakriti and therefore more susceptible to conditions such as flatulence, stuttering, and rheumatism. Deranged vata is also associated with certain mental disorders due to excited or excess vayu (gas), although the Ayurvedic text Charaka Samhita also attributes "insanity" (unmada) to cold food and possession by the ghost of a sinful Brahman (brahmarakshasa).

Ama (a Sanskrit word meaning "uncooked" or "undigested") is used to refer to the concept of anything that exists in a state of incomplete transformation. With regards to oral hygiene, it is claimed to be a toxic byproduct generated by improper or incomplete digestion. The concept has no equivalent in standard medicine.

In medieval taxonomies of the Sanskrit knowledge systems, Ayurveda is assigned a place as a subsidiary Veda (upaveda). Some medicinal plant names from the Atharvaveda and other Vedas can be found in subsequent Ayurveda literature. Some other school of thoughts considers 'Ayurveda' as the 'Fifth Veda'. The earliest recorded theoretical statements about the canonical models of disease in Ayurveda occur in the earliest Buddhist Canon.

Practice

Ayurvedic practitioners regard physical existence, mental existence, and personality as three separate elements of a whole person with each element being able to influence the others. This holistic approach used during diagnosis and healing is a fundamental aspect of Ayurveda. Another part of Ayurvedic treatment says that there are channels (srotas) which transport fluids, and that the channels can be opened up by massage treatment using oils and Swedana (fomentation). Unhealthy, or blocked, channels are thought to cause disease.

Diagnosis Ayurveda has eight ways to diagnose illness, called nadi (pulse), mootra (urine), mala (stool), jihva (tongue), shabda (speech), sparsha (touch), druk (vision), and aakruti (appearance). Ayurvedic practitioners approach diagnosis by using the five senses. For example, hearing is used to observe the condition of breathing and speech. The study of vulnerable points, or marma, is particular to Ayurvedic medicine.

Treatment and prevention Two of the eight branches of classical Ayurveda deal with surgery (Śalya-cikitsā and Śālākya-tantra), but contemporary Ayurveda tends to stress attaining vitality by building a healthy metabolic system and maintaining good digestion and excretion. Ayurveda also focuses on exercise, yoga, and meditation. One type of prescription is a Sattvic diet.

Ayurveda follows the concept of dinacharya, which says that natural cycles (waking, sleeping, working, meditation etc.) are important for health. Hygiene, including regular bathing, cleaning of teeth, oil pulling, tongue scraping, skin care, and eye washing, is also a central practice.

Substances used

The vast majority (90%) of Ayurvedic remedies are plant based. Plant-based treatments in Ayurveda may be derived from roots, leaves, fruits, bark, or seeds; some examples of plant-based substances include cardamom and cinnamon. In the 19th century, William Dymock and co-authors summarized hundreds of plant-derived medicines along with the uses, microscopic structure, chemical composition, toxicology, prevalent myths and stories, and relation to commerce in British India.Pharmacographia Indica , A history of principal drugs of vegetable origin in British India – Volume 1, William Dymock et al. (1890), London Triphala, an herbal formulation of three fruits, Amalaki, Bibhitaki, and Haritaki, is one of the most commonly used Ayurvedic remedies. The herbs Withania somnifera (Ashwagandha) and Ocimum tenuiflorum (Tulsi) are also routinely used in Ayurveda.

Animal products used in Ayurveda include milk, bones, and gallstones. In addition, fats are prescribed both for consumption and for external use. Consumption of minerals, including sulfur, arsenic, lead, copper sulfate and gold, are also prescribed. The addition of minerals to herbal medicine is called rasashastra.

Ayurveda uses alcoholic beverages called Madya, which are said to adjust the doshas by increasing pitta and reducing vatta and kapha. Madya are classified by the raw material and fermentation process, and the categories include: sugar-based, fruit-based, cereal-based, cereal-based with herbs, fermented with vinegar, and tonic wines. The intended outcomes can include causing purgation, improving digestion or taste, creating dryness, or loosening joints. Ayurvedic texts describe Madya as non-viscid and fast-acting, and say that it enters and cleans minute pores in the body.