Gravity does its best to pull the blood to the feet, but it is not ensuring a return trip. Because, in the human body, the major foot arteries are the farthest away from the heart, many circulatory problems will first display themselves in the feet.
The arteries carry blood away from the heart and the veins carry blood returning to the heart and lungs for regeneration - for nutrients and oxygen - after the blood's supply of oxygen has been used up to nourish the tissues of the body.
There are two main arteries that supply the feet with the essential blood supply: the dorsalis pedis artery and the posterior tibial artery. These two major arteries distribute oxygenated blood through smaller arterioles to the many tissues of the feet. Healthy arteries have thick walls that are strong and elastic. To accommodate the pressure created by the pumping of the heart, they must stretch with each heartbeat.
Half the deaths in the United States each year are caused by cardiovascular diseases. The single greatest killer of Americans today is hardening of the arteries or arterioslcerosis. when this occurs, there is a lack of blood-flow to a given area of the body, particularly the feet, since they are farthest from the heart.
Reduced blood-flow to a part of the body means that the muscles may become oxygen-deficient. Some symptoms of oxygen-deficiency are a cramping pain in the calf and lower leg. At the same time the feet may become cold. (Though not all muscle cramps should be interpreted as a sign of cardiovascular disease, if you suspect a problem seek medical advice.) Sometimes a person with a circulatory problem will develop thick and brittle toenails.
Veins are thinner-walled than arteries. Since veins are returning blood back to the heart, they are under less pressure. Veins are more numerous than arteries and contain about 70 percent of the body's blood at any one time. Since blood returning to the heart from the lower part of the body must move against gravity, most of the larger veins contain one-way valves to keep the blood from pooling in the feet and legs, or moving backwards.
Another well-known circulatory problem is varicose veins. Varicose veins are veins that have a valve problem. when this happens, blood moves backward and the veins become swollen. These veins swell, because of the blood they are being forced to hold, until eventually they do not function properly. The larger, deeper veins develop valve problems, and at that point the used blood re-routes through smaller, more superficial veins. The blood can pool, the veins can stretch, and flaps in the vein can separate. The National Heart Lung and Blood Institute describes this phenomenon as veins becoming "like overstretched rubber bands."
Those swollen veins can make legs aching or feeling swollen. They're physically visible. But they're also telling you something -- your body is carrying way too much sugar in the bloodstream.
Sugar and carbohydrates absorb water. Fat and protein repel water. The elasticity of the blood vessel wall gets dilated from gravity -- and those vessels have to process more because we're eating too much sugar. The human body was built to function on fat-based energy.
Watch for these symptoms:
Chronic Venous Insufficiency (CVI) needs to be treated as soon as possible. It won't just go away. If untreated, the pressure and swelling increase until the tiniest blood vessels in the legs (capillaries) burst. When this happens, the overlying skin takes on a reddish-brown color and is very sensitive to being broken if bumped or scratched. This can cause local tissue inflammation and internal tissue damage. Or worse, it can leads to open sores (ulcers) on the skin surface. These venous stasis ulcers can be difficult to heal and can become infected. When the infection is not controlled, it can spread to surrounding tissue, a condition known as cellulitis.
If you have swollen legs and ankles, aching legs, or any of the other symptoms, talk to your doctor and ask about treatment.