Swelling of the calf is a pit when pressed, the possible causes are lower extremity venous thrombosis, renal edema, cardiogenic edema and so on. 1. Lower extremity venous thrombosis: once the veins of the legs are blocked, it will affect the normal blood flow, the metabolism of the legs decreases, and the swelling will appear slowly, and it is difficult to recover immediately by pressing with the hands, resulting in the phenomenon of swollen calves and puddle when pressed. 2. Nephrogenic edema: seen in all kinds of nephritis and nephropathy, its occurrence is related to the decrease of glomerular filtration function and the increase of water and sodium reabsorption in renal tubules. 3. cardiogenic edema: the most common in the right heart failure, can also be seen in narrow pericarditis, pericardial effusion and other diseases, mainly lower extremity venous reflux obstruction resulting in elevated venous pressure caused by the phenomenon will also occur. Calf swelling a press a pit may also have other reasons, it is recommended to go to the regular hospital in a timely manner, improve the relevant examination, clear cause, under the guidance of the doctor to give targeted treatment or treatment.