Feasibility Study of a New Peripheral Oedema Monitor for Heart Failure

Inclusion Criteria: * Inpatients with admission for de-compensated heart failure requiring increase or initiation of diuretic therapy for fluid congestion. * Patients attending cardiology outpatients at the Royal Brompton hospital with a diagnosis of heart failure and fluid retention. * Cardiology patient without fluid retention (cardiology controls) Non-Cardiology patient without fluid retention (controls) Exclusion Criteria: * Patients unable to provide informed consent. * Unstable arrhythmias in previous 48 hours * Systolic BP\<90mmHg or need for inotropic support * Ulceration on lower limbs (below shin) - excluded from water displacement but could have image recording and calipers * Inability to transfer from bed to chair * Patients with broken skin or cellulitis will not have their foot volume measured using the water displacement equipment to reduce the risk of infection for the patient and other participants.