Siddha YI-ABC

Siddha system of Medicine is one of the indigenous AYUSH systems, predominantly practiced in parts of South India and across the countries where Tamil speaking people reside. The concept of Udal iyal (Body constitution) in Siddha system is in line with the current practice of personalised and preventive medicine in the global context. Udal iyal is based on the fundamental principle, Muth (Three)-thaadhu (3 vital life forces, ie Vali, Azhal and Aiyam forming 7 different types of Udal iyal or Yakkai Ilakkanam. These 7 types are brought under 3 major classifications, Vali Udal, Azhal Udal and Aiya Udal. Distinctive in their physical and psychological aspects, an accurate assessment of the Udal iyal will pave the way for predicting health status of the patient thus contributing to diagnosis and planning treatment and prevention strategies. A team of researchers from Siddha Central Research Institute (SCRI) functioning under the Central Council of Research in Siddha (CCRS), under the Ministry of AYUSH. Govt. of India have devised Yakkai Ilakkanam (YI) tool. This was possible through comprehensive review of literature and research. [Project title: “Validation of Siddha Udal iyal Inventory – YI for Assessment of Body Constitution (ABC): a descriptive cross-sectional study”]. The YI tool has 3 divisions, each covering the physical, mental and functional profiles of the human body. Answering a set of questions on these aspects together with basic socio-demographic details will help to ascertain the Udal iyal, Yakkai Ilakkanam/Body constitution of an individual and classify as Vali, Azhal or Aiyam thegi. Based on this information, an individualized dietary and lifestyle modifications is advised. Such body constitution – Udaliyal analysis based on Siddha principles will promote healthy behaviours towards preventing lifestyle disorders in individuals and thus, in the long-run will contribute to overall improvements in population health.

  • Scientific Advisory Board of CCRS: 2nd SAB-Approved, Dated: 16 June 2016
  • Sanction order: 1-52/2016-CCRS/Tech./Hqrs/341 (L) Date: 17-01-2017
  • Institutional Human Ethics Committee Approved Number: IHEC/SCRI(CCRS)-1/2018-19/01, Dated: 18th May 2018
  • Clinical Trial Registry of India Registration: CTRI/2018/09/015652, Dated: 07 Sep 2018
  • Project Evaluation Monitoring Committee (PEMC): Approved, Dated: 16 April 2019.

YI-ABC Flow Chart Phase 1 YI-ABC Flow Chart Phase 2

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Date: 03 May 2018
List of Subject Matter Experts participating the FGD Meeting:

  1. Dr. P. Jayaprakash Narayanan, Chairman, SPC, CCRS.
  2. Dr. G. Ganapathy, Member-General Body, CCRS.
  3. Dr. T. Anandan, Former Director I/c, SCRI, Chennai.
  4. Dr. S. Indhira, Chief Medical Officer, NFSG, Dept. of Indian Medicine & Homeopathy, Govt. of Puducherry.
  5. Prof. Dr. K. Kanagavalli, Principal, Govt Siddha Medical College, Chennai.
  6. Prof. Dr. S. K. Sasi, Reader, HOD, Dept. of Noi Nadal, GSMC, Chennai.
  7. Dr. K. Rajalakshmi, Associate Professor, Dept of Siddha, The Tamil Nadu Dr. MGR Medical University, Chennai.
  8. Dr. J. Jeyavenkatesh, Siddha Physician, Kokila Siddha Hospital & Research Centre.

Date: 16 April 2019
List of Members - Project Evaluation Monitoring Committee:

  1. Prof. Dr. S. K. Sasi, Reader, HOD, Dept. of Noi Nadal, GSMC, Chennai.
  2. Prof. Dr. G. J. Christian, Professor & Head, Dept. of Noi Nadal, NIS.
  3. Dr. S. Valarmathi, Research Officer (Statistics), The Tamil Nadu Dr. MGR Medical University, Chennai.

Central Council for Research in Siddha


Central Council for Research in Siddha (CCRS) is the apex body for research in Siddha system of Medicine. The Council functions under the Ministry of AYUSH, Govt. of India. The primary function is for undertaking, coordinating, formulating, developing and promoting scientific research in Siddha system. This covers research in drug, medicinal plants, fundamental principles, classical literature and systematic documentation. The activities are carried out through 8 peripheral Institutes/Units – three located in Tamil Nadu, one each in the States of Kerala, Karnataka, Andhra Pradesh and New Delhi and the Union Territory of Puducherry. Besides research, the Council offers clinical and consultancy services and capacity building programmes.

Siddha Central Research Institute


Siddha Central Research Institute was established in 1971 at Arumbakkam, Chennai, Tamil Nadu under the aegis of CCRS, Ministry of AYUSH, Govt. of India. This Institute houses facilities for trans-disciplinary research in Siddha system of medicine through various departments. The Department of literary research does collection, preservation, annotation, cataloguing, transcription and publication of palm leaf manuscripts and rare Siddha books. The Department of Clinical Research has 50 bedded hospital facility and does clinical trials adhering to Govt. of India guidelines. Department of Biochemistry and Pathology supports clinical research projects. SCRI has been identified as a Peripheral Pharmacovigilance Centre (PPvC) of the Pharmacovigilance Programme of India. The Department of Pharmacognosy helps in identification of herbal drug and contributes to Siddha Botanical Standardization and Siddha Pharmacopoeia. Standardization of drugs for clinical trials are carried out by the Department of Chemistry. The Department of Pharmacology carries out the pre-clinical studies of safety and efficacy of Siddha formulations.

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Siddha Central Research Institute (Central Council for Research in Siddha Ministry of AYUSH, Govt. of India) Arumbakkam, Chennai - 600106 .



This web app has been developed for the benefit of the students, research scholars, academicians with life sciences background, Siddha practitioners, and particularly for common public. All possible efforts have been made to ensure the correctness of the contents collected from various literatures and features of the software. However, SCRI, CCRS and Ministry of AYUSH government of India shall not be responsible for any error in the content made inadvertently. All possible corrective measures will be taken once, such errors are brought to the notice. This web app version reflexes the point estimate of your body constitution and your predominant constituent (either Vali or Azhal or Aiyam).

Important Notes

Important Notes

This web application contains a set of questionnaire for making the assessment of body constitution of individual who take part in the survey. After completion of the survey, your constitution will be declared based on the responses given by you for the survey questions. Once the assessment completed, an fundamental information (Do’s and Don’ts and preventive measures) will be sent to the registered mail id provided by you.

Designed and Developed by

Designed and Developed by

ABC - Project Team
Literary Research and Documentation Department (LR&DD)
Department of Clinical Research (DCR)
Siddha Central Research Institute (CCRS)
Arumbakkam, Chennai -600106
Tamil Nadu.

ABC - Project Team

ABC - Project Team

Project Monitor

Prof. Dr. K. Kanakavalli, Director General, Central Council for Research in Siddha

Prof. Dr. R. S. Ramaswamy, Former Director General, Central Council for Research in Siddha

Principal Investigator

Dr. M. Kannan, Research officer (Siddha) Sci-II


Dr. P. Sathiyarajeswaran, Director I/c, Siddha Central Research Institute

Research Associate

Dr. G. Kiruthiga, Siddha Physician

Technical Reviewer

Dr. P. Manickam, Scientist-E, National Institute of Epidemiology (ICMR)

IT Team

Mrs. M. Rajalakshmi, IT Consultant

Miss. M. KodimalarGomathi, IT Consultant