Edema: Fluid Retention Causes (Kidney/Liver Disease, Vascular Permeability, Low Albumin, Lymphatic Blockage) and Treatments (Diuretics, Compression, Elevation)

Edema = abnormal interstitial fluid accumulation causing palpable swelling.

Pathophysiologic Categories

• Increased Hydrostatic Pressure: Heart failure (↑ CVP), venous obstruction (DVT, compression), renal Na⁺/H₂O retention.
• Decreased Oncotic Pressure: Hypoalbuminemia (nephrotic syndrome, cirrhosis, malnutrition, protein-losing enteropathy).
• Increased Capillary Permeability: Inflammation (sepsis, burns, angioedema), cytokines (VEGF, histamine).
• Lymphatic Obstruction: Surgery (lymphadenectomy), radiation, filariasis, malignancy.

Treatment by Mechanism

• Diuretics: Loop (furosemide), thiazide, K⁺-sparing — for volume overload.
• Compression Therapy: Gradient stockings (20–30, 30–40 mmHg), wraps, pumps — for venous/lymphatic edema.
• Elevation: >Heart level — gravity-assisted drainage.
• Lifestyle: Na⁺ restriction (<2 g/day), weight management, exercise.
• Treat Underlying Cause: HF optimization, albumin infusion (selective), immunosuppression, surgical lymphovenous anastomosis.

Red Flags: Sudden unilateral leg edema (DVT), pulmonary edema (orthopnea, hypoxia), anasarca with oliguria — seek emergent care.