Primary cause of lower extremity venous ulcers: venous insufficiency Definition of lower extremity venous ulcers (VLU): Lower extremity venous ulcers (VLU) are open skin wounds caused by chronic venous insufficiency (CVI) and venous hypertension, often located on the inner calf, between the knee and ankle joints. The treatment period is usually long. Compression bandage therapy is the gold standard of treatment, but the use of compression bandages is low in China. In addition to issues such as product accessibility and health insurance payment, the level of knowledge and practical experience of wound therapists can be a limiting factor. The understanding of venous insufficiency is the basis for effective treatment of VLU, and most of the current domestic treatment for VLU is still only for wounds, and the use of pressure bandages is also low, which directly leads to poor treatment results and high recurrence rates. Therefore, wound therapists should fully learn and understand the mechanisms of lower extremity venous insufficiency in order to be informed when developing and implementing treatment strategies.