The depression of the calf that does not rebound when pressed proves that there is tissue edema in the area. Edema can be caused by a variety of factors, including local and other factors. Localized edema can be caused by diseases such as varicose veins of the saphenous veins, connective tissue diseases, deep vein thrombosis, etc. This kind of edema is mostly unilateral and can be accompanied by redness, swelling, heat and pain. Other factors such as cardiac insufficiency, mucous edema, hypoproteinemia, renal insufficiency, uremia, cirrhosis, etc. are common, and their edema is mostly bilateral or generalized, without other symptoms.