The goal of this observational is to study the prevalence of distinct congestion phenotypes and study their association with response to therapy and outcomes in acute heart failure patients. The main question\[s\] it aims to answer \[is/are\]: * Primary objective: to study the prevalence of distinct congestion phenotypes * Other objectives (including): * Response to therapy as assessed by * Natriuresis after 24 hours * Rehospitalization and/or deats after 6 months * Length of hospital stay * Congestion at discharge * Changes in filling pressures over time * Relationship between liver stiffness, as assessed with Fibroscan and congestion * Substudy: glycosaminoglycan netword and endothial glycocalyx Participants will undergo several extra study related measurements: * Assessment of filling pressures with ultrasound * Ultrasound investigation of the lungs and kidneys * Fibroscan of the liver * Sidestream darkfield imaging sublingual * As part of substudy GLYCO-AHF: skin biopsy to determine glycocalyx, as well as salt and water content. * As part of substudy PREACH-AHF: the effects of peripheral venous congestion and endothelial dysfunction on a large screen of plasma proteins