Dr Ong completed her respiratory training in South-West London and during this time, also completed a PhD at the Allergy and Clinical Immunology Department in the National Heart and Lung Institute. She later acted as the Clinical Tutor for the Diploma and MSc in Respiratory Medicine courses at the Royal Brompton Hospital.

She was appointed as a consultant at St George’s Hospital in 2005 where she sub-specialises in lung cancer. A year later, she also became an honorary senior lecturer with St George's, University of London.

She has been the Training Programme Director for Respiratory Medicine in South-West Thames, Care Group Lead for the Respiratory Medicine department and Associate Director of Medical Education for SGH.

Dr Ong was in the first cohort of participants who completed the Postgraduate Certificate in Healthcare Education at St George’s Hospital in 2004. In her role as an honorary senior lecturer, she co-runs the Graduate Entry Programme Life Support and Body Systems modules and has just started as SSCT lead.

In terms of post-graduate education, she started and ran Acute Medicine Update, Respiratory Radiology and Tips for teaching courses in collaboration with colleagues.