Elevating the leg is recommended if there is edema in the ankle for 40 days after the ankle fracture, but is not necessary if the edema has completely subsided. The purpose of sleeping with the leg elevated is mainly to promote blood circulation and return venous blood from the lower extremities to the heart, thus avoiding bruising of the lower extremities. The need to sleep with the legs elevated depends mainly on whether the patient still has edema in the feet. For some patients, the swelling of the foot can be completely reduced in 3~4 weeks, so there is no need to elevate the leg while sleeping. For patients whose edema has not completely disappeared, elevating the leg while sleeping can help the edema subside, reduce the pressure on the foot, avoid edema at the fracture site, and prevent the accumulation of tissue fluid that causes discomfort. When the edema completely subsides, the patient enters the rehabilitation exercise period, when walking on the ground, there will also be the re-establishment of venous return, there will also be a process of swelling, in this case, the patient sleeps with the leg elevated is also conducive to the reduction of swelling.