Chronic peripheral oedema: the critical role of the lymphatic system.

important sign of ill health in clinical medicine. It may occur in the lungs (pulmonary oedema), the abdominal cavity (ascites) and other body cavities (synovial, pericardial and pleural effusions) but in this article only peripheral (subcutaneous) oedema is discussed. In medical practice peripheral oedema tends to get pigeonholed according to possible systemic or peripheral causes eg heart failure, nephrotic syndrome, venous obstruction or lymphoedema. This viewpoint fails to appreciate the many dynamic physiological forces contributing to oedema development and in particular the central role of the lymphatic drainage system in tissue fluid balance. Consequently, the clinician’s approach to chronic oedema is often misguided and the necessary medical intervention inappropriate, for example, empirical use of diuretics. In this article we propose a system for managing peripheral oedema, which is based on physiological principles, that can then guide treatment. Why is chronic oedema important?