Swollen feet in hemiplegic patients may be dangerous. Swollen feet in hemiplegic patients are commonly associated with edema in the low hanging area due to reduced activity, sunken edema due to hypoproteinemia, deep vein thrombosis in the lower extremities, and edema due to impaired reflux. The first two are not dangerous, but deep vein thrombosis is a very dangerous disease. This condition is caused by the reduced activity of the limb on the hemiplegic side, which stagnates blood and forms a thrombus in the deep vein, which is formed by the aggregation of red blood cells and is a red thrombus that is easily dislodged. When the thrombus is dislodged, it will enter the heart through the inferior vena cava and then be pumped into the lungs. If the thrombus enters the lungs, it will lead to pulmonary embolism and the patient will suffer from respiratory failure and death, so it is a very dangerous disease. It is necessary to ask for emergency consultation of vascular surgery and surgical treatment for it. If there is no condition for surgery, patients should use anticoagulant to try to dissolve the thrombus.