Distribution of accumulated fluid is the important element in the differentiation of peripheral edema resulting from different etiologies. Isolated upper extremity edema is rare and is usually caused by obstruction of the superior vena cava by a malignancy. The cause of unilateral edema of a lower limb can usually be determined by the history (heart, liver or kidney disease, trauma, malignancy, radiation or surgery), a physical examination (distribution of edema, stigmata of infection, trauma, malignancy or organ failure) and appropriate laboratory and other tests. Determining the etiology of bilateral lower extremity edema requires a similar approach; this condition may be the result of systemic conditions, drug use, lipidema or idiopathic edema, in addition to obstructive causes and chronic venous states. Algorithms, based on the patient's history, physical examination and diagnostic tests, can help guide physicians to the correct diagnosis.