9781422288450

High Blood Pressure

Another serious and extremely common form of car- diovascular disease is high blood pressure (also called hypertension). Each time your heart beats, it pushes blood through approximately 60,000 miles (about 96,600 kilometers) of blood vessels. The pressure on

blood vessel walls as blood pushes through them coupled with blood vessels’ natural resistance to blood flow creates what we know as blood pressure. It is a measure of the force your blood exerts on vessel walls when your heart pumps. Perhaps it is easiest to understand high blood pressure as simply having an overworked heart and overstressed blood vessels. If the pressure is too great, then it can damage (or even rupture) tiny blood vessels, especially in your eyes, brain, kidneys, and heart. Consequently, monitoring blood pres- sure is essential for everyone, but particularly for those who are overweight or obese since they’re at greater risk for high blood pressure. Once consid- ered an adult problem, doctors now see many cases in children and youth. In fact, an estimated percent of U.S. children have high blood pressure, and obesity causes the overwhelming majority of such cases. As with coronary artery disease, the precise cause of hypertension is unknown, yet one of three of the following situations usually exists: blood vessels are too narrow, which makes the heart work harder to push blood through; blood vessels are stiff and can’t expand with blood surges; and the bloodstream contains excessive sodium and water, increasing fluid in the blood. Increased fluid means increased pressure against vessel walls. Any of these conditions can result in hypertension, but the ailment is most commonly associated with the narrowing of arteries excess weight causes. As arteries gradually narrow with attached plaque, the heart can only get blood through if it pumps with excessive force. Blood pressure rises with each heartbeat and falls with each lull between beats as your heart

52 / Health Issues Caused by Obesity