[1] Fernando was a consultant physician in diabetes and the endocrinology department of the Sri Jayawardanapura General Hospital and a senior lecturer in the faculty of medicine at the University of Colombo.

[9][10][11] Fernando was a charter member of the board of study in medical administration at PGIM Colombo,[12][13] was involved in the specialist training of doctors in Sri Lanka through the Royal College of Physicians[14][15] and was connected to efforts to prevent discrimination against diabetes patients.

[41] Fernando chaired the Endocrine and Metabolic Disease Trust, based in Dehiwala-Mount Lavinia, Ratmalana, from 1990 to 2004;[42][43] helped establish a renal dialysis unit[44] and transit home[45] for patients and families visiting the University of Sri Jayewardenepura faculty of health sciences and its teaching hospital in 1998;[46] set up computer servers linking the John Pease Diabetes Centre in Sutton-in-Ashfield, England and centres in Sri Lanka to aid education in Sri Lanka,[47] and assisted in disaster relief after the 2004 Indian Ocean earthquake and tsunami.

[48] Fernando was a school prefect,[49] won awards in rugby and athletics (finished second in the 1973 400m junior national AAA championships),[50][51] was active in classical, English debating and drama societies[52][53] and was part of the rugby union Royal-Thomian rivalry[54][55] on the 1975 S. Thomas' College team coached by Quentin Israel, called the best Thomian team by sports journalist Sharm de Alwis.

[60] Fernando moved to the United Kingdom in 2005, where he has been a consultant endocrinologist, Head of the Sherwood Forest Hospitals Foundation Trust's Department of Diabetes and Endocrinology at King's Mill Hospital[61] and a member of the foot-care team,[62] associate medical director for clinical governance[63] and member of a trial steering committee.