The measurement of leg circumference in patients with lower extremity venous thrombosis is generally recommended to measure the circumference of the thigh at 15 cm from the upper edge of the patella and 10 cm from the lower edge of the patella or the circumference of the thickest part of the calf muscle belly in both lower extremities. The first measurement should be marked at the measurement location so that subsequent measurements can be taken at the same location with relatively small errors, and generally 2-3 measurements should be taken for the average. During the measurement process, it is recommended to move gently, avoid squeezing and massaging, and try to carry out symmetrical measurements on both sides to compare the circumference between the affected limb and the healthy limb, and to compare the affected limb before and after treatment. Detailed records are made every day, including the difference in circumference of the healthy side of the thigh and calf before treatment and the difference in circumference of the affected side of the thigh and calf after treatment. Dynamic comparisons were made based on the detailed recorded data to assess the effect of treatment and the reduction of leg swelling.