Modern day management of a unilateral pleural effusion.

Over 50 systemic conditions may affect the pleura and, thus, unilateral pleural effusions may present for a variety of reasons. Investigating the cause is essential to providing appropriate management. Various pleural interventions are available in current practice, but have varying diagnostic sensitivity. It is, therefore, vital to consider the intervention with the highest diagnostic yield appropriate to the particular clinical situation. The diagnostic pathway in unilateral pleural effusion is increasingly outpatient based, avoiding hospitalisation, which is particularly relevant with the recent COVID-19 pandemic. © Royal College of Physicians 2021. All rights reserved.