Post-surgical edema is mainly due to the following three common clinical reasons, first, the most common is the postoperative fasting for a long time, resulting in malnutrition, hypo-proteinemia and edema, which can be manifested as ascites, lower limb edema. It is necessary to improve the nutritional status of the patient by total gastrointestinal nutrition, supplementation of human albumin or diuretic treatment can be relieved to disappear. Secondly, long-term bed-ridden cause lower limb lymphatic reflux obstruction manifested as lower limb edema, advise patients to get out of bed as soon as possible to promote lymphatic reflux can improve the symptoms. Thirdly, we need to be highly alert to the lower extremity deep vein thrombosis caused by poor blood viscosity and long-term bed rest in elderly patients, and we need to perform lower extremity vascular ultrasound to make a clear diagnosis. In case of lower extremity DVT, it is necessary to place a filter or even thrombolytic therapy.