Siddha medicine is the oldest and the foremost of all other medical systems of the world. The word "Siddha", a Tamil word, means an object to attain perfection or heavenly bliss. Siddha generally refers to 'Athma Siddha' that is a 8th Supernatural Power.
Those who attained or achieved the above said powers are known as "Siddhars". There were 18 important Siddhars in olden days and they developed this system of medicine. Hence, it is called Siddha Medicine.