Dr Angus studied medicine at Glasgow University and post qualification initially trained in general internal medicine and respiratory medicine in hospitals around Glasgow before completing his training in Liverpool. 

He held a British Lung Foundation Research Fellowship and in addition he spent a period of attachment to academic intensive care units in London and Chicago.

He was appointed to Aintree Chest Centre, Aintree University Hospital, Liverpool, in January 1996. In addition to a general respiratory practice he was medical director of the hospital high dependency unit (HDU) which he helped constitute and establish. He has developed an outpatient non-invasive ventilation (NIV) service and an inpatient ventilation centre. He previously led the severe asthma service at Aintree Chest Centre and has served as the UK secondary care assembly member for GINA the Global Initiative for Asthma.

He also developed, in conjunction with the local community trust, a home care scheme (ACTRITE) for COPD. Publishing the outcomes in the BMJ this is the forerunner of current intermediate care services. He has contributed to the BTS intermediate care and hospital at home guidelines for COPD, and NICE guidelines for the management of motor neurone disease (MND), including NIV, working with the Royal College of Physicians (RCP) London and NICE on this. Current research interests include exploring the impact of computer-guided consultations in asthma, COPD and sleep medicine together with Telehealth in the optimisation and remote monitoring of patients on ventilation in particular in MND. 

Dr Angus is active in education and is the Respiratory Lead for the medical course at Liverpool University. He is also interested in the post qualification training of professionals in the respiratory field. He was Regional Respiratory Advisor for the RCP London from 2009 to 2019 and chairman of the Education Charity Respiratory Education UK, which in the last 20 years this has developed diploma, degree and masters courses in Respiratory Disease Management. This has now merged with Education for Health of which he is co-chair.