Heart failure is a significant cause of morbidity and mortality worldwide. While the aetiology varies and there are a wide variety of treatment options, a large amount of the morbidity related to heart failure is due to fluid retention and the symptoms of volume overload. Multiple neurohormonal pathways are activated in heart failure, and contribute to the symptoms of fluid retention and volume overload. Although not ideal, diuretic therapy is one of the mainstays of treatment of fluid overload in patients with heart failure. This review focuses on the pathophysiology of heart failure leading to volume overload, the different classes of diuretics used in alleviating the symptoms of fluid retention, their mechanisms of action within the kidney, and strategies for using them in ways that minimize their deleterious effects in patients with heart failure.