by Dr. Richard Edelson Blood Clots: What To Do To Prevent Them Blood clots are a real hazard following surgery. Your orthopedist will give you complete instructions on how to avoid blood clots. You must follow these instructions closely. Here Are The Signs to Watch Out For If you have a blood clot in your leg, you may experience the following: Swelling the lower leg, specifically the foot, calf and ankle. You may feel calf pain. You may see tenderness and redness around the kn