Swelling in the calves may be related to prolonged standing, varicose veins in the lower limbs, right heart failure and other factors. 1. Prolonged standing: part of the population may be due to sudden prolonged standing or walking, squatting, etc., the blood return to the lower limbs is not smooth, and swelling of the lower legs occurs. 2. Varicose veins of the lower limbs: venous valves function is reduced, hindering the venous blood return in the lower limbs, causing obstruction of venous return in the lower limbs, and swelling of the lower limbs after the accumulation of venous blood in the lower limbs. 3. Right heart failure: it leads to stagnation and edema in the body circulation, which leads to the increase of venous hydrostatic pressure and edema in the interstitial space of the tissues, and the earliest manifestation is the edema in the low-hanging parts of the body. In addition to the above, it can also be seen in other causes such as hypoproteinemia. When there is edema in the lower legs, it is recommended to consult a doctor in time, follow the doctor’s instructions for further examination, clarify the cause with the help of the doctor, and actively cooperate with the doctor to deal with or treat it.