This can cause leg swelling, changes in the skin texture and color, and skin ulcers. Veins are blood vessels that return blood from the body to the heart and lungs to get more oxygen. Veins require the muscles in our feet and legs to return the blood, against gravity, to the heart. To help this process, veins have a series of one-way valves in them that prevent back flow. Obesity, inactivity, and aging can contribute to the weakening of or damage to the valves.
Some people inherit weak valves.
This can lead to pooling of blood, called stasis, in the veins. This blood stasis causes abnormally high pressure in the veins and swelling in the legs, which gradually gets worse. Sometimes there is so much swelling that tiny drops of plasma, the pale yellow fluid part of blood, leak out of the skin. The tiniest blood vessels, called capillaries, can burst under high pressure. When this happens, red blood cells are released directly into the nearby tissue.