RT Journal Article SR Electronic T1 Breathomics for the clinician: the use of volatile organic compounds in respiratory diseases JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP thoraxjnl-2020-215667 DO 10.1136/thoraxjnl-2020-215667 A1 Wadah Ibrahim A1 Liesl Carr A1 Rebecca Cordell A1 Michael J Wilde A1 Dahlia Salman A1 Paul S Monks A1 Paul Thomas A1 Chris E Brightling A1 Salman Siddiqui A1 Neil J Greening YR 2021 UL http://thorax.bmj.com/content/early/2021/01/07/thoraxjnl-2020-215667.abstract AB Exhaled breath analysis has the potential to provide valuable insight on the status of various metabolic pathways taking place in the lungs locally and other vital organs, via systemic circulation. For years, volatile organic compounds (VOCs) have been proposed as feasible alternative diagnostic and prognostic biomarkers for different respiratory pathologies.We reviewed the currently published literature on the discovery of exhaled breath VOCs and their utilisation in various respiratory diseasesKey barriers in the development of clinical breath tests include the lack of unified consensus for breath collection and analysis and the complexity of understanding the relationship between the exhaled VOCs and the underlying metabolic pathways. We present a comprehensive overview, in light of published literature and our experience from coordinating a national breathomics centre, of the progress made to date and some of the key challenges in the field and ways to overcome them. We particularly focus on the relevance of breathomics to clinicians and the valuable insights it adds to diagnostics and disease monitoring.Breathomics holds great promise and our findings merit further large-scale multicentre diagnostic studies using standardised protocols to help position this novel technology at the centre of respiratory disease diagnostics.