Siddhars developed, among other branches of a vast knowledge-system, what is now known as Siddha medicine, practised mainly in Tamil Nadu as Traditional native medicine.

A rustic form of healing that is similar to Siddha medicine has since been practised by experienced elderly in the villages of Tamil Nadu, and is popularly known as Paatti Vaitthiyam, Naattu marunthu and Mooligai marutthuvam

They are also founders of Varmam - a martial art for self-defence and medical treatment at the same time. Varmams are specific points located in the human body which when pressed in different ways can give various results, such as disabling an attacker in self-defence, or balancing a physical condition as an easy first-aid medical treatment.

Siddhars have also written many religious poems.

One of the best-known Siddhars was Agasthyar who is believed to be the founding father of Siddha culture. The Community people take up trekking to most thrilling Agasthiar Hills from South Kerala to worship Sage Agasthiya. Large number of traditional Siddha practitioners do their service to the society in Nanjil territory around Marundhuvaazh Malai, in Sencottah territory around Pothigai Hills and in Kuthirai Mozhi Forests around Thiruchendur/Udangudi/Sathankulam towns.

It is believed that most of them have lived for ages, in a mystic mountain called Sathuragiri, near Thanipparai village in Tamil Nadu. Sathuragiri can be approached from moutain trekking routes such as Saptoor in Madurai district, Varushanadu near Theni and Thaanipparia near Vathirayiruppu. From 5 years old children to 80 years old elderly women and men take up this exploring trekking on every full moon day and new moon day in South Tamilnadu.

After 8 kilometers of trekking in steep hills in deep jungle maintained by Forest Department, there is still a lot to be explored on the system of Siddhar and their wisdom.

The Nadar families of Saptoor have contributed to the development of the temples in Sathuragiri. Few noted Nadar families of Madurai and Ayyappa Bhakthas associated with Aruppukottai Nadar Uravinmurai Amudhlingeswrar temple have also contributed to great extent along with others to the preservation and distribution of Holy water in Sathuragiri Hills which is very sweet and is believed to have healing power.

Sivakasi Hindu Nadars Uravinmurai Mahamai Fund Committee has spent considerable wealth and efforts to distribute to the sweet drinking water from Underground storage to above ground tanks and then through individual tapes to all the pilgrims.

This mystic divine mountain attracts thousands of Sadhus who gets detached from family and material life the world and who wish to explore Siddha way of life in a detached manner. In these days they are called as Paradhesis by common people who chase this materialisit ambitions of human life and some time not given proper treatment in the earth. But in this Sathuragiri mountain Sadhus are given a decent consideration and respect. On the Aadi Amavasya day Sadhus select a chief elder among them who get a special deserved meal in the God' sanctum sanctorum to share the meal with other dignified people. A selected group Sadhus & Paradhesis after this event come down to various places in and around Madurai and Theni. They are given special treatment by Saalichandai Nadar Uravinmurai Committee before dispersal and their regrouping in the next Aadi amavasya.

Annadhana schemes with partcipation of Nadar elders from Madurai, Sivakasi and Vathirayiruppu are organised in a efficient manner in the mountain to serve thousands and thousands of pilgrimages who throng on Full moon and no moon day at the sathuragiri hills.