High output heart failure (HOHF) is a particular type of heart failure with multiple etiologies but a similar underlying mechanism, namely a decrease in systemic vascular resistance, in some instances associated with increased metabolic requirements. This leads to neurohormonal activation, fluid and sodium retention and a chronic hyperdynamic state resulting in a classic congestive state associated with clinical signs of high output. While no clear definition of HOHF exists, such findings and an increase in cardiac output (cardiac index >4 L/min/m2) strongly suggest the diagnosis. This probably under-diagnosed entity should actively be sought, particularly in obese patients and/or patients labelled with heart failure with preserved ejection fraction (HFpEF). Treatment and prognosis depend on the etiology.