About
Daniel M. Ratnarajah, MD is a board-certified internist who has practiced in Oneida, New York for over two decades. He earned dual medical degrees, first from the University of Jaffna Medical Faculty in Sri Lanka and then from the National University of Ireland, Galway, where he received honors in Biochemistry, Physiology, and Behavioral Science. He completed an internship at Ennis General Hospital in Ireland before training in internal medicine at the University of Connecticut Health Center in Farmington, Connecticut, finishing his residency in 1994.
Dr. Ratnarajah is passionate about holistic care, weaving nutrition, exercise, stress management, and spiritual wellness into his clinical approach. He serves as Chairman of the Department of Internal Medicine at Oneida Healthcare, a role he has held since 2017, and sits on the Oneida Healthcare Board as a trustee. He also serves as a physician at the Oneida Indian National Health Clinic and as Assistant Division Physician for Troop D of the State Troopers. The Oneida Healthcare Foundation honored him with the Golden to the Core Award in 2013. He speaks English and Tamil, and members consistently praise his thoroughness, responsiveness, and bedside manner.
Education & Training
Undergraduate
St. John's College, Jaffna, Sri Lanka - General Certificate of Education Advanced Level, Pre-medical (1981)
Medical School
University of Jaffna, Medical Faculty, Jaffna, Sri Lanka - Bachelor of Medicine, Bachelor of Surgery (1982); National University of Ireland, Galway, Ireland - Bachelor of Medicine, Bachelor of Surgery (1990), Honors in Biochemistry, Physiology and Behavioral Science
Residency
Internal Medicine, University of Connecticut Health Center, Farmington, CT (1991-1994)
Additional Training
Internship: Ennis General Hospital, Ennis, Ireland (1990-1991)
Languages
English, Tamil
Conditions Treated
Who is Dr. Ratnarajah right for?
Dr. Ratnarajah is a strong fit for adults seeking a long-term, relationship-driven approach to internal medicine. Patients managing type 2 diabetes, high cholesterol, or hypertension benefit from his proactive, prevention-first mindset. He works well with patients who want a physician to coordinate their specialist care directly. Anyone who values 24/7 physician access and same-day availability will find his practice a natural fit.
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Frequently Asked Questions
Dr. Ratnarajah specializes in internal and preventive medicine. He focuses on managing chronic conditions including type 2 diabetes, high cholesterol, and hypertension. His approach targets root causes through lifestyle interventions alongside clinical management.
Dr. Ratnarajah takes a holistic view of health, addressing nutrition, exercise, stress management, and spiritual wellness together. He builds a personalized wellness plan with each patient rather than reacting to illness alone. Patients describe him as thorough, proactive, and highly responsive.
Yes, Dr. Ratnarajah holds board certification in internal medicine. He completed his residency training at the University of Connecticut Health Center in Farmington, Connecticut, from 1991 to 1994.
Dr. Ratnarajah has practiced in Oneida, New York for over two decades. He has spent more than 23 years working in internal medicine and maintains deep ties to the local medical community.
Yes, Dr. Ratnarajah holds privileges at Oneida Healthcare Center and visits patients there directly. He coordinates closely with hospital physicians to keep care transitions smooth and continuous.
Yes, Dr. Ratnarajah has established personal relationships with numerous specialists in and around the Oneida area. He works directly with them to ensure continuity and quality throughout a patient's care.
Dr. Ratnarajah speaks English and Tamil.
Dr. Ratnarajah serves as Chairman of the Department of Internal Medicine at Oneida Healthcare, a position he has held since 2017. He also sits on the Oneida Healthcare Board as a trustee, serves patients at the Oneida Indian National Health Clinic, and acts as Assistant Division Physician for Troop D of the New York State Troopers.
Yes, the Oneida Healthcare Foundation presented Dr. Ratnarajah with the Golden to the Core Award in 2013. He also received the Board Leadership Award from M&T Bank in 2010 and a Chamber of Commerce Award in 2005.
Doctor profile last updated April 4, 2026