After a femoral neck fracture, many patients develop swollen feet, either to the back of the foot or the entire lower leg from calf to thigh. There are many reasons for foot swelling, and different approaches should be taken depending on the reasons. After the muscle activity is reduced, the pumping action of the muscle is weakened, and it cannot push the vein or lymphatic fluid back. At the same time, after hip injury, the surrounding soft tissues also tend to have different degrees of atrophy, and the decrease in muscle strength can lead to impaired blood circulation in the lower limbs, resulting in swelling of the limbs. There is also a condition that is not caused by muscle atrophy or reduced muscle activity in the lower extremity, but is caused by deep vein thrombosis in the lower extremity. In other words, thrombosis is formed in the deep vein, which blocks the main vein of return flow, and the blockage also leads to swelling of the foot. And not only cause foot swelling, once the embolus is dislodged, it can reach the brain, heart and even lung, causing brain infarction, heart infarction, lung infarction and so on, which are the important causes of patients’ life-threatening and death. Therefore, for most of the clinically clearly diagnosed DVT, timely treatment is necessary to avoid complications and prevent the embolus from dislodging and endangering the patient’s life.