Nephrotic syndrome, regardless of its etiology, is a thrombophilic condition, especially when serum albumin is less than 20 to 25 g / l. the frequency of events thrombosis is estimated at nearly 50% of patients. Venous thrombosis accounts for 75 to 80% of thrombotic events and their prevalence is estimated 25 to 40%. They are dominated by thrombosis renal vein (20 to 30%) manifested by pain lumbar, gross hematuria, increased the size of the kidneys and a worsening of the function kidney. Deep vein thrombosis members below are reported in approximately 25% of patients. Other jurisdictions may be involved (subclavian veins, jugular, mesenteric or cerebral). Arterial thrombosis is rare and concern 3 9% of patients. All territories are concerned. The risk of coronary thrombosis is multiplied by 5.5 and that of deaths from coronary thrombosis 2.8.