What are the basic principles of Siddha?

Siddha suggests that the physical structure of the universe and human are basically made up of five elements. They are Nilam (Earth), Neer (Water), Thee (Fire), Kaatru (Air), and Vin (Sky). These names represent the properties of the elements and not the exact substances.

Three forces/faults (Mukkuttram) The physiological function of the body is maintained by three forces. They are Vali (Vatham), Azhal (Piththam), and Aiyam (Kapam).  When these three forces are in equilibrium, the results will be healthy. Any disproportion will result in diseases. In disease, these three forces are called three faults (Mukkuttram).