When Less Is Not More: Exploring the Current Evidence, Practices, and Perspectives on Fluid Restriction in Patients with Heart Failure

Fluid restriction has long been a cornerstone of heart failure (HF) management, traditionally recommended at 1.5-2 liters/day for patients with advanced HF or hyponatremia to prevent volume overload. It was based on the rationale that limiting fluid intake reduces preload, alleviates congestion, and counteracts neurohormonal activation. However, this practice has been driven more by clinical judgement and physiological reasoning than high-quality evidence. Recently, emerging data have challenged its universal use, raising concerns about quality of life, adherence, and dehydration risk. This narrative review explores the evolving role of fluid restriction in chronic HF, with a focus on the balance between physiological rationale and patient-centered outcomes. It critically examines historical practices, summarizes key clinical trials, including the Fluid Restriction in Heart Failure versus Liberal Fluid Uptake (FRESH-UP) trial, and evaluates the risks of both fluid overload and dehydration. The review further considers current guideline positions, highlights gaps in evidence, and discusses emerging perspectives that advocate for a more individualized, quality-of-life-oriented approach to fluid management in HF. Evidence supporting routine fluid restriction has been limited and inconsistent. While small studies suggested possible benefits in hyponatremic patients, others reported minimal clinical impact and increased thirst. The FRESH-UP trial, the largest to date, found that liberal, thirst-guided fluid intake was safe and reduced thirst distress without increasing hospitalizations, mortality, or renal dysfunction. These results challenge routine restriction and support a more individualized approach. Emerging evidence suggests that strict fluid restriction offers little clinical benefit for most stable chronic HF patients. A more liberal, individualized approach improves comfort without compromising safety and reflects the evolving direction of HF care.