Siddha medicine is one of the two ancient traditional systems of India. First one is “Ayurveda”, which flourished in north India and became popular all over the country and also in abroad, and the second one is “Siddha”, which originated from Tamil Nadu, a south-east state of India and practiced mostly in and around areas of its origin. SSM has been in existence and is being practiced for past 2000 years; however the printed Siddha literatures are available from 18th century onwards. Before that they were documented on palm leaves by different authors.
The word “Siddha” denotes “Siddhi” which means achievement in life arts such as philosophy, yoga, wisdom, alchemy, medicine and above all the art of longevity. The persons, who obtained this Siddhi, were respectfully called “Siddhars”. Siddhars can also be called spiritual scientists of Tamil Nadu who explored and explained the reality of nature and its relationship to man by their yogic awareness and experimental findings. They postulated the concept of spiritualism for self-improvement, and the practices initiated by them came to be known as the "Siddha System”. It is believed that Siddhi was obtained by 18 highly experienced and intuitive Siddhars who were believed to cure innumerable diseases.
Agasthiyar, one among the 18 Siddhars is believed to have contributed more in the development of SSM, whose life period is approximately between fifth to sixth centuries. He is considered as the ‘’Hippocrates of Siddha medicine and also one of the greatest philosophers of India. Some of his works are still in standard books of medicine and surgery, which are in the daily use among the Siddha medical practitioners. The SSM is mainly concerned with the development of drugs, which have high potency and long life for their use in future. It also aims to activate the generation of cells and to maintain the longevity.
Siddha system is based on 96 principles (thathuvams) which are broadly classified under the following categories: 5 elements (pancha bhutam), 5 sense organs (pori), 5 functions of sense organs (pulan), 5 motor organs (kanmenthiriyam), 5 perception of senses with the help of five sense organs (gnanenthriyam), 4 intellectual faculties (karanam), 1 wisdom of self realization (arivu), 10 channels of life force responsible for the dynamics of prana (naadi), 10 vital nerve forces which is responsible for all kinds of movements (vayu), 5 visceral cavities (asayam), 5 five states of the human body or sheath (kosam), 6 stations of soul (aatharam), 3 regions (mandalam), 3 impurities of the soul (malam), 3 humours (tridosham/ tridosha siddhantam), 3 physical bindings (eadanai), 3 cosmic qualities (gunam), 2 acts (vinai), 8 passions (ragam), 5 states of consciousness (avasthai). Many of these principles are found in Ayurveda also but some of them are very unique to Siddha system alone.
The common specific features of these two systems are: tridosha siddhantam; wind (vatham), bile (pittam) and phlegm (siletuman), pancha bhuta theory; space (aakasam), air (vayu) ,fire (thee) , water (neer) ,earth (munn), three gunas; subtle (sattva), activity (rajas), gross (tamas), and six kinds of tastes (arusuvai).
However, certain differences between them can be cited. Siddha system differs in localizations of three doshas in the body when compared to Ayurveda. There are certain other distinguishing features, which have been described in the following sections.