Varicose veins
PKGhatak, MD
Inside the veins, at certain intervals, there are valves. Valves prevent blood from moving downwards to the dependent parts of the body and legs. Valves break up the blood column in short segments, thereby lowering the pressure within the veins. Blood flows by gravity from the head and neck to the right atrium of the heart. The pressure generated by skeletal muscle contractions and smooth muscle contractions of the vein wall creates the pressure gradient that propels blood from the dependent parts of the body toward the heart. The pressure inside the veins is very low, but higher than the right atrial pressure, which is generally 1 to 3 cm of water.
You can easily see the healthy veins on the back of your hands. If you follow a long vein of your legs, you will notice small bulges along the walls. These are valves.
When standing in one spot for long hours, blood tends to remain stagnant in the legs. The blood column exerts pressure on the valves. After many years in sedentary workers, the valves become lax and unable to hold back blood, and become incompetent. These veins become tortuous and darker in color, and the condition is called varicose veins. Often, there is also a genetic predisposition for varicosity, but the precise mode of inheritance is not known.
Incompetent veins cause fatigue of the legs and may cause a sense of fullness and pain in the legs when walking for some time. In older people, loss of muscle, the veins become easily visible, and if the valves are incompetent, the stagnant blood thins out the skin, and ulcers and clots develop. This is called venous thrombosis. Though many other factors favor blood clotting in the leg veins but prolonged immobility in the elderly is the main cause of venous clots.
It is a good idea to remain active even if you have a job requiring standing for long hours. You must walk around every so often to help blood circulate better in your legs, thereby preventing varicose veins.
edited May 2025.
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