Ayurveda or ayurvedic medicine is a system of traditional medicine native to the Indian subcontinent and a form of alternative medicine. The oldest known ayurvedic texts are the Suśruta Saṃhitā and the Charaka Saṃhitā. These Classical Sanskrit encyclopedias of medicine are among the foundational and formally compiled works of ayurveda.
By the medieval period, 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, and, along with siddha and Traditional Chinese medicine, form the basis for systems medicine.
Safety concerns have been raised about Ayurveda; for instance, two U.S. studies found that about 20 percent of Ayurvedic Indian-manufactured patent medicines contained toxic levels of heavy metals such as lead, mercury and arsenic. Other concerns include the use of herbs containing toxic compounds and the lack of quality control in Ayurvedic facilities.
In classical Sanskrit literature, Ayurveda was called "the science of eight components" (Sanskrit aṣṭāṅga अष्टांग), a classification that became canonical for ayurveda. They are:
Kāya-chikitsā: "cure of diseases affecting the body" (general medicine)
Kaumāra-bhṛtya "treatment of children" (paediatrics)
Śhalya-chikitsā Surgery, "removal of any substance which has entered the body (as extraction of darts, of splinters, etc.)"
Śālākya-tantra "cure of diseases of the eye or ear etc. by sharp instruments" (ophthalmology/ENT[dubious – discuss])
Bhūta-vidyā "treatment of mental diseases supposed to be produced by demoniacal influence" (demonology / exorcism/psychiatry[dubious – discuss])
Agada-tantra "doctrine of antidotes" (toxicology)
Rasayana-tantra "doctrine of elixirs"
Vājīkaraṇa tantra "doctrine of aphrodisiacs"