Hindu Systems of Medicine are those which have its roots in Hindu scriptures and its practicing is in conformity with the Hindu religious concepts. Ayurveda and Siddha are the two systems, falling under this group. Both these systems have its origin from pioneering rishis of Hindu religion. Both these systems have the same fundamental theory for diagnosing diseases viz. Tridosha or that of three fundamental humors. Vatha, Pitta and Kapha are called Tridoshas or Three Humors(These will be discussed in detail in the ensuing sections).
Different Books indicate different genealogy for the Ayurveda from a particular point, that is from Indra. It maintains that Ayurveda originated from Brhma and from him Daksha, from Daksha to Aswani Kumaras from them to Indra. According to Susrutha Samita this lineage flowed down to Dhahanwantari, Aupadhena, Vaithana, Aurabra, Poushakalavatha, Karaveeja, Gopurakshita, Bhoja and others. In accordance with Charaka Samhita from Indra, the lineage is to Bharadwaja, Atherya, Punarvasu, Agnivesha, Bhela, Jathukarna, Parasara, Hareetha, Ksharpani and others. As per Kashyapa Samhita the lineage is towards Kashyapa, Vasihta, Atri-Bhrugu, and their disciples.
There need not have to be any confusion about these genealogies as three distinct ones, as the ancestors only convey that three different branches of Ayurveda grew from same source under three great Acharyas. The exact life periods of these Acharyas are unclear. Above all, the origin of Ayurveda can be seen in Rigveda and Atharva Veda before being systematized under the above great seers. Apart from these historicities, there is a prominent mythological version concerning the origin of Ayurveda that it is with Dhahanwantari, who appear with nectar, in a grant churning process.
As hinted in the beginning, Ayurveda and Siddha are part of the Hindu religion and its diagnosis, treatment, preparation of medicines, dispensing of medicine to a patient, accepting a reward/fees for the treatment etc. are all formulated in conformity with the tenets of the fundamental concepts of Hindu Religion or Sanathana Dharma. These contours drawn by the ancestors for Ayurvedic and Siddha treatments are always in collision course with the modern concepts of treatments propounded by Allopathy and other systems. To a very great extent, the difference in outlook of these medical systems emanates chiefly from the religions to which its respective progenitors belonged to. If to put the reason behind this in the simplest way, one can say that, while the Hindu religion and the likes do not view the human body or for that matter any life form as a physical machine alone, other sematic religions consider it as a physical machine only. This fundamental difference only worked as root reason for the modern treatment systems to acquire its current monstrous form, to the extent that treatments need not have to have any ethicalities or treatment is impossible without a set of machines or equipments and a human by birth is not bound to know about his body and that knowledge is falling only under the exclusive realm of a qualified modern doctor, that too of allopathic system.