At first there was the Central Council for Research in Ayurveda & Siddha. (The principles and doctrines of Ayurveda and Siddha are similar.) Many years later, in 1995 the Department of Indian System of Medicine and Homeopathy (ISM&H) was set up. In 2003 it was renamed the Department of Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homeopathy (AYUSH). In November 2014 it became the Ministry of AYUSH.

A joint venture between the Government of India and the state government of Tamil Nadu, the National Institute of Siddha (NIS) at Chennai is an autonomous organisation under AYUSH. The Institute conducts a postgraduate course for students, provides medical care, conducts research and promotes the science.

The Siddha system of medicine dates back to around 12000 BC. The word Siddha means established truth. The origin is attributed to Siddha Agastiyar.

It is believed that the Tridoshas control the basic physiological functions of the body along with 5 sub-doshas for each of the 3. When the normal equilibrium of these tridoshas/humours of the body – air, fire and water – is disturbed, disease occurs. The Tridoshas are vaadham/vata (lightest, blue), pittham/pitta (medium, red)and kapam/kapha (heaviest, yellow) and the ideal ratio between them 4:2:1 respectively.

The cause for imbalance could be the environment, climatic conditions, diet, physical activities or stress. Diet and lifestyle play a major role in maintaining good health and curing problems.

The Siddha Materia Medica is based on Humoural Pathology. It asserts that all substances of the animal, the vegetable and the mineral kingdom contain one or more of these three humours in their composition and therefore, diet should play an important role in the maintenance of these humours in preventing diseases and ailments.

Since the treatment is mainly aimed to restore equilibrium of the 3 humours of the body, cleansing procedures are advised: vomiting, purgation, enema, and nasal drops.

Coral, conch, horn of deer, musk and honey are some of the animal ingredients utilised. Inorganic chemical compounds are also used as therapies for treating diseases: Siddha literature lists 220 minerals which include metals, salts, mercury and arsenic compounds, as well as other minerals. And, several medicinal plants or herbs utilised fall under IUCN’s rare endangered and threatened categories.

Siddha physicians may also apply pressure on vital points or neuromuscular junctions, to treat some ailments.