Siddha
The Siddha system is one of the oldest systems of medicine in India. The term 'Siddha' means achievement. The 'Siddhars' were saintly souls who had achieved the Supreme knowledge. Eighteen Siddhars seem to have contributed towards the development of this medical system. Among them Saint Agasthyar is the foremost. All the authoritative literature of the Siddha system is in Tamil. The Siddha system is largely therapeutic in nature.
All existing things in this universe (macrocosm) are formed by the five basic elements, namely the Earth, Water, Fire, Air and the Space, which are called as the 'Fundamental Boothas'. These elements constituting the human body and other worldly substances are explained as "Pancheekarana". Any one of these elements cannot act independently by itself and has to act in co-ordination with the other elements. The living creatures and the non-living things are made up of 96 principles including the five elements, seven "Dhatus" and three humours. 'Disease' is a condition in which there is derangement in the five elements, which alters the three humours and is reflected in the seven physical constituents. The change could be an increase or decrease in the equilibrium.
The Materia Medica of the Siddha system is very vast compared to other indigenous systems of medicine. Herbs, metals, minerals and organic matters are used in this system and the usage of metals and minerals is far more advanced. Surgical methods like incision, excision, heat application, bloodletting and leech application are practised besides purgation, vomiting, fasting, steam and oil application, physical and solar therapies.