Hi, he might have developed deep vein thrombosis. Deep vein thrombosis (DVT) occurs when a blood clot (thrombus) forms in one or more of the deep veins in your body, usually in your legs. Deep vein thrombosis treatment is aimed at preventing the clot from getting any bigger, as well as preventing the clot from breaking loose and causing a pulmonary embolism. After that, the goal becomes reducing your chances of deep vein thrombosis happening again. Consult Vascular surgeon...