Dr Henry Navaratnaraja Rajaratnam was educated at The Royal College, Colombo, where he had a brilliant career culminating in being awarded the F.E. Weerasooriya Memorial prize for the best performance in the Medical entrance of 1955. He obtained his MBBS in 1962, M.D. Ceylon in 1969, and M.R.C.P. UK in 1973. He has been trained in 5 specialties: Dermatology, General Medicine, Endocrinology, Cardiology, and Respiratory Medicine.

His Endocrinology training in the U.K. was under the late Dr David Ferriman at the North Middlesex Hospital in London, of “Ferriman and Galwey hirsutism Index” fame. He was also Registrar in Cardiology and Chest Medicine over a period of 2 years at the Harefield Hospital, London. He returned to the Island in 1973 and served as Physician in Kandy, Ratnapura, and Kurunegala Hospitals. In 1984, he was appointed as the first Physician to the newly designated Teaching Hospital at Colombo North, Ragama. In 1991, he assumed the post of Consultant Physician at The National Hospital Colombo, and from there, he retired from Government Service in 1997. He has continued to practice as a Physician (total of 52 years) and as an Endocrinologist in the private sector to date.

He obtained Fellowships from The Royal College of Physicians London, the Ceylon College of Physicians, The American College of Endocrinology, Honorary Fellowships from The Royal Australasian College of Physicians, the Sri Lanka College of General Practitioners, and The Sri Lankan College of Endocrinology.

He has served as The President of the Ceylon College of Physicians in 1996, President of the Endocrine Society of Sri Lanka from 1993 to 2003 (10 years), and the founder Patron of the Endocrine Society of Sri Lanka from 2006 to date. He is also one of the Founder Patrons of the South Asian Federation of Endocrine Societies from 2013 to date. Presently, he is a Trustee of the Ceylon College of Physicians. He has been a Council member of the Ceylon College of Physicians for 25 years up to 2017. He has been the compiler of the “Medicine Update” of the Ceylon College of Physicians from 1994 to date (27 years) and the “Endocrine Update” of the Endocrine Society of Sri Lanka, which he established in 1995 (26 years), to date. He has also served for 6 years in the Asian Pacific Committee of the Royal Australasian College of Physicians, which enabled him to place 17 Post Graduates for their higher training abroad. He used his good offices to initiate Paediatric Endocrinology training in Melbourne, Australia.

He is credited with conducting the 1st clinical Endocrinology clinics in State Hospitals, viz North Colombo Hospital, Ragama in 1985, which he continued at the National Hospital Sri Lanka from 1991 to 1997. His greatest contribution to Endocrinology was to forward a memorandum to the Ministry of Health on the necessity of recognizing and establishing Endocrinology, Diabetes, and Metabolism as a sub-speciality in Sri Lanka. He was nominated as the first Chairman of the committee responsible to prepare the course of study for Endocrinology in Sri Lanka in 1996, and this programme for this sub-speciality was established in 1997. He has up to date participated in the training of 55 Post Graduates in Endocrinology.

As a pioneer Endocrinologist, he initiated the monthly clinical meetings of the Endocrine Society and taught many generations of Medical graduates and Post graduates and has continued to be a trainer in Endocrinology in the private sector until 2021. His main interest has been in autoimmune thyroiditis, diabetes, snake bite, pituitary disease, and Bariatric surgery. He has delivered two orations: The Prof K. Rajasuriya oration on “Autoimmune thyroiditis – why the fascination” and the inaugural Deshamanya S. Ramachandran oration on “Diabetes – is it a surgically treatable disease?” on the metabolic effects of Bariatric surgery, a programme which he initiated in 2003.

He was the joint author of the first description of “Amylase-rich pleural effusion in perforation of the oesophagus” in the Medical literature. He was also the first to describe the coeliac disease, pituitary disease following viper bite, and Tick-borne Typhus in Sri Lanka. He was also the pioneer in Bariatric surgery in Sri Lanka along with the Late Dr M. Ganesharatnam, Surgeon.