Venous ulcers are open sores that typically develop on the lower legs and ankles due to poor blood circulation. They occur when veins struggle to return blood to the heart, leading to increased pressure in the veins. This pressure can cause the skin to break down, resulting in painful wounds that may take a long time to heal. These ulcers are often associated with conditions like chronic venous insufficiency and can be exacerbated by factors such as obesity, age, and a history of deep vein thrombosis. Treatment usually involves improving blood flow, managing symptoms, and promoting healing through dressings and compression therapy.