Congestion is not only considered a cardinal sign of heart failure but also the main mechanism responsible for heart failure decompensation episodes. It is now accepted that congestion determines the phenotype of heart failure presentation in the acute setting either by volume overload, volume maldistribution or both. Recognizing the mechanism responsible for congestion is paramount, as it implies that different therapeutic strategies are required to achieve decongestion. Although achieving complete decongestion is considered the target, in most cases of acute heart failure episodes, this is hampered by various factors that lead up to residual congestion which is considered one of the strongest predictors of future cardiovascular events and poor outcomes. In this review, by immerging into the pathophysiology mechanisms of congestion, unraveling its phenotypes and discussing new diagnostic tools for targeting therapy, we are trying to acknowledge the importance of “the congestion phenomenon” and its scale among heart failure patients which is of pandemic proportions.