What Causes Swelling In The Arms, Stomach And Thighs?

My father is 89 years old. His symptoms: swollen hand, swollen upper arm, belly, thigh. He recently suffered a burst vein in the muscle of his hip. He is in terrible pain, was in the hospital, and was released to a rehab. He has a hematoma in his hip area 12 inches long and 9 inches wide. The swelling has not gone down. He was on blood thinners to prevent a stroke but he was taken off. He also has had a quadruple bypass and has a pacemaker and a valve replacement. We are concerned that he is at rehab when the doctors have not established what is actually wrong with him and why the swelling is so bad and has not gone down. Any diagnosis would be helpful.