What should you do if a dvt grows longer?

Extension of DVT: Deep vein thrombosis is a blood clot that may propagate (elongate) and threaten direct extension into central veins or a piece may break off and travel (embolize). Anticoagulation is performed to prevent the above, but vein ligation, filter insertion, clot lysis or thrombectomy may be utilized. Initially, stockings and nonstrenuous ambulation may help prevent elongation.