Table 1.

Common causes of leg edema in the western world.

Unilateral		Bilateral
Recenta	Chronicb	Recenta	Chronicb
Unilateral DVT	Primary venous disease	Bilateral DVT	Chronic venous disease/post-thrombotic syndrome
Ruptured Baker's cyst	Post-thrombotic syndrome	Acute heart failure	Pulmonary hypertension
Ruptured leg muscle	Iliac vein compression	Acute renal/liver failure	Heart/renal/liver failure
Compartment syndrome	Lymphedema	IVC thrombosis	Idiopathic edema
Intramuscular hematoma	Vascular malformation	IVC tumors	Chronic IVC occlusion, IVC aplasia/hypoplasia
Infection	Reflux sympathetic dystrophy	Drugs	Drugs (see Table 2)
Superficial vein thrombosis	Mass/tumorc	Bilateral infections	Lymphedema
Mass/tumorc	Venous advential cystic disease		Lipedema
Fracture	Infection		Pregnancy, premenstrual edema
Sprain/strain	Static foot disorders		Obesity
Insect/animal bites	Radiation		Malabsorption syndrome, hypoalbunemia
	Atrophy/hypertrophy		Spinal cord injury/immobility
	Overgrowth syndromes		Static foot disorders
			Thyroid disease
			Obstructive sleep apnea

Note: Arteriovenous fistulas involving large vessels can present with acute or chronic and unilateral or bilateral swelling. More commonly it presents as a chronic condition.

^aRecent definition includes acute (<3 days) and sub-acute (3 days – 3 months).

^bChronic definition >3 months.

^cCan occur in the pelvis or extremity. If chronic, more likely to be benign.