Part of your circulatory system in your lower limb, the venous supply, takes the blood that travelled to your arms, legs and organs through your arterial blood supply, back to the heart. This is the way that the used blood that has delivered the oxygen and nutrients is taken away to be cleaned by your kidneys and liver and made ready to pick up oxygen and nutrients to take through the arterial system to ‘feed’ your skin, muscles and other tissues.
Your heart helps pump arterial blood out around your body, but your venous supply relies on muscle contractions and valves in the veins to move blood along and keep it there. If you are not moving around much or your veins have had some changes that prevent the valves working properly, then you can get swollen discoloured ankles and legs where the venous blood is not being removed efficiently. This can also be complicated where some medical conditions like heart failure, kidney disease or poor lymphatic drainage cause fluid to retained in the body and can cause swelling in the legs and feet. This can cause the skin to stretch and breakdown resulting in venous ulcers; these typically appear on the legs but can appear on the feet in some cases. For more information on how to reduce swelling in the lower limb, prevent venous ulcers or help manage them please visit NHS Leg Ulcer information.