<p>Heart failure is a leading cause of hospitalization worldwide, and congestion is the predominant cause of heart failure symptoms and hospitalization. The primary therapy used to treat and prevent congestion has historically been loop diuretics. However, many patients are discharged from hospital with residual congestion, which is associated with persistent heart failure symptoms, adverse outcomes and hospital readmission. Multiple medical strategies and devices have been and are being investigated with the aim of improving decongestion and subsequent heart failure outcomes. Numerous questions exist about the design of clinical trials to test emerging medical and device therapies, including the magnitude of benefit on congestive, kidney and post-discharge outcomes relative to conventional decongestion practices, and how best to implement novel therapies. In this Review, we discuss emerging medical and device strategies targeting congestion in patients with heart failure.</p>