From the Guidelines
Pedal edema is most commonly caused by fluid retention in the lower extremities, resulting from conditions such as venous insufficiency, heart failure, kidney disease, liver disease, and medication side effects, as well as factors like prolonged standing or sitting, pregnancy, and lymphatic system disorders. The causes of pedal edema can be multifaceted, involving various physiological and pathological processes. Some of the key causes include:
- Venous insufficiency, where weakened valves in leg veins allow blood to pool 1
- Heart failure, which reduces the heart's pumping efficiency 1
- Kidney disease, which impairs fluid elimination 1
- Liver disease, particularly cirrhosis 1
- Medication side effects from drugs like calcium channel blockers, NSAIDs, thiazolidinediones, and steroids 1
- Prolonged standing or sitting 1
- Pregnancy 1
- Lymphatic system disorders 1 Other contributors to pedal edema include low protein levels in blood (hypoalbuminemia), salt-rich diets, and obesity 1. It is essential to identify and address the underlying cause of pedal edema to provide effective management, which may involve elevating legs, wearing compression stockings, reducing salt intake, and taking prescribed diuretics like furosemide 20-40mg daily or spironolactone 25-100mg daily 1. In some cases, pedal edema can be a symptom of a more severe condition, such as erythrodermic psoriasis, which requires distinct treatment approaches, including systemic therapies like oral cyclosporine, acitretin, MTX, and TNF-alfa inhibitors 1. Therefore, it is crucial to evaluate persistent or severe edema by a healthcare provider to rule out serious underlying conditions and provide appropriate treatment.
From the Research
Causes of Pedal Edema
- Pedal edema can be caused by the use of dihydropyridine calcium channel blockers, which are a class of antihypertensive agents 2.
- The pathogenesis of renal sodium and water retention in cardiac failure, cirrhosis, and the nephrotic syndrome may also lead to pedal edema 3.
- Pedal edema is prevalent in community-dwelling adults without clinically recognized cardiovascular disease and is associated with future hospitalized heart failure 4.
- Congestive heart failure (HF) is a complex disease state characterized by impaired ventricular function and insufficient peripheral blood supply, leading to fluid retention and pedal edema 5.
Underlying Mechanisms
- The interplay between the heart and the kidneys plays a central role in edema formation in HF, involving multiple interdependent mechanisms such as hemodynamic alterations and activation of neurohormonal systems 5.
- Activation of neurohormonal factors including renin-angiotensin-aldosterone system (RAAS), sympathetic nervous system (SNS), endothelin-1 (ET-1), and anti-diuretic hormone (ADH) due to reduced cardiac output (CO) and renal perfusion can lead to sodium and water retention and vasoconstriction 5.
- The supremacy of deleterious neurohormonal systems over beneficial natriuretic peptides (NP) in HF can lead to persistent sodium and water retention and cardiac remodeling 5.