Edema in ankleBy Mayo Clinic staff
Original Article: http://www.mayoclinic.com/health/medical/IM04177
Edema in ankle
Swelling of the foot, ankle and leg can be severe enough to leave an indentation, or "pit," when you press on the area. This swelling (edema) is the result of excessive fluid in your tissues — often caused by congestive heart failure or blockage in a leg vein.