Lower extremity edema results from an imbalance between capillary hydrostatic pressure, oncotic pressure, and lymphatic drainage, leading to fluid accumulation in the interstitial space. Most cases are bilateral, typically due to systemic causes of volume overload such as heart failure, cirrhosis, or kidney dysfunction. Unilateral edema is more often due to localized pathology, including deep venous thrombosis, cellulitis, or trauma. Edema is a common presenting symptom and may be associated with pain, reduced mobility, and functional impairment. Initial evaluation should include a history and physical examination with attention to risk factors, symptom duration, laterality, precipitating factors, and associated signs and symptoms. Laboratory tests and diagnostic imaging are selected based on clinical suspicion, in some cases aided by tools such as the Wells criteria for deep venous thrombosis. Management targets the underlying etiology. Edema due to systemic causes often improves with disease-specific therapy. Edema due to chronic venous insufficiency and lymphedema respond to compression therapy. Lipedema is the painful localized accumulation of subcutaneous adipose tissue and treatment is focused on symptom management.

Case 4. BC is a 59-year-old with a history of hypertension, hyperlipidemia, type 2 diabetes, moderate obesity, and remote tobacco use. He presents with a concern of worsening bilateral lower extremity swelling. He states that the nature of his work involves standing for most of the day, and by the end of the day his legs are swollen. On most mornings, the swelling has completely subsided, but over the past few weeks it has been persistent. He denies any recent chest pain, shortness of breath, or palpitations, but believes that he has recently gained a few pounds.