Chronic rhinosinusitis (CRS) is a protracted inflammatory condition with global societal and financial burden. [1][2][3] Its prevalence is estimated to be 10-28% based on self-reported symptoms alone, 4,5 and about 4-9% when endoscopy 6 or imaging is applied. 7,8 Real world data suggest that nearly half of CRS patients have uncontrolled disease based on visual analogue scale for rhinosinusitis. 9 This subgroup has significant disease burden as these patients require longterm follow-up, medication and often repeat sinus surgeries. 10 Traditionally, CRS is classified based on the presence or absence of nasal polyps. It is evident that this classification based on a visual trait is probably an overly simplistic representation of a heterogenous condition with a spectrum of clinical presentations and severity. Hence in recent years, there is increasing interest in uncovering the inflammatory mechanisms, or endotypes, of CRS. With the advent of novel treatment options, including biologicals, the ability to accurately define endotypes and predict response to specific treatments via biomarkers is important in order to provide individualised patient care. 11 Research in CRS is a continually evolving field. The objective of this review is to update readers on the recent, important developments in the field of CRS in adults. This includes the changes in the latest edition of the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS2020), novel biomarkers, biologicals in the treatment of CRSwNP and the implications of the COVID-19 on the