Dr Bradley graduated in 1981 with a basic medical degree from Trinity College having also taken an intercalated year to complete a BA(Mod) [equivalent to BSc] in Physiology.  Upon completion of his intern year in the Meath Hospital Dublin he joined the Vocational Training Programme for General Practice in Cork.

Following his training, he moved to the UK taking up a position as Lecturer in General Practice at the University of Manchester.  He was also appointed as a Principal in General Practice at the Robert Darbishire Practice in Rusholme, Manchester. While in Manchester he completed his MD (doctoral degree) undertaking research on ‘uncomfortable’ prescribing decisions (of GPs).

In 1992 he was appointed as a Senior Lecturer in General Practice at the University of Birmingham and Principal in General Practice at the Lee Bank Group Practice.

In 1997 he was appointed the Foundation Professor of General Practice at University College Cork (UCC) and Principal in General Practice at the McDonald Practice in Cobh, Co Cork.  He has acted as an advisor to the Irish health service on diabetes, cardiovascular disease, antibiotic stewardship and cardiovascular disease.

He was a member of the University Ethics Committee and the Clinical Ethics Committee of the Cork Hospitals and Chair of the Research Ethics Committee of the Irish College of GPs (ICGP). He was also Secretary of the ICGP in 2003 and a Board Member for several years.  He was vice-chair of the Board of Governors of the Mercy University Hospital, Cork.

In 2017 he was awarded a Leadership Award by UCC and, on his retirement from UCC in 2023, a Lifetime Achievement Award by the School of Medicine.  In 2017 he was awarded a Fulbright/ Health Research Board Health Impact Award to undertake research on the opioid crisis in Oklahoma, USA.