What is venous stasis; how does it occur?

Stagnant blood flow: Venous stasis exists when venous blood flow is diminished. Either by reduced venous return, diastolic dysfunction or by increased size of the vessels (varicose veins).

Vein pooling: Veins return blood to the heart. Venous stasis occurs when there is reduced flow or pooling in the veins, almost always occurring in the legs. The most common cause is when the one-way valves don't work well, leading to venous reflux, or back flow, with blood pooling in the veins. Other causes can be from damage caused by blood clots or other blockages. See a vein specialist/phlebologist.

Venous insufficiency: A better name for venous stasis is venous insufficiency. Stasis implies that blood isn't moving when, in fact, venous blood is moving--the wrong way. Normally venous valves direct blood flow up and out of the leg but when the valves stop working properly, blood flows backwards, pressure builds up and the pain and skin changes of "stasis" occur. More often than not, the cause is hereditary.

Valves malfunction.: Venous stasis is due to venous insufficiency which is a result of the valves in the venous system malfunctioning . This can be due to the valves in the deep system, superficial system or connecting system. Deep system valve malfunction could be due to prior clots, superficial problems could lead to varicose veins and perforator malfunction could lead to venous ulcers.

Venous stasis: The issue is one of vein hypertension, due to the impeded flow of blood returning to the heart, especially in the legs. This is due to incompetent valves in the veins. With increased blood pooling in the legs comes 'heavier' legs, swelling, pain from swelling, pitting in the skin, leakage of fluid and blood into the tissues, leakage of the fluid onto the skin causing maceration and destruction...

Skin changes: Venous stasis is caused by valve problems that allow blood from deep high-pressure veins to enter low-pressure veins just under the skin. These veins enlarge, letting fluid through the walls (swelling), letting blood through (discoloration) and finally having so much back pressure that nutritious arterial blood cannot enter an area of the skin resulting in ulcers. It is treated by laser ablation.