2011年5月3日 星期二

Hard Truths About Blood Pressure

Fully 60 percent of people with diabetes have high blood pressure. And the chances of a person with diabetes having serious heart disease are several times greater than for people without diabetes. Which is good reason to understand blood pressure, to take it seriously, and to do what it takes not to let this plot take its natural, sad course.

High blood pressure isn’t new. For the last century or so, that simple measurement has helped identify people whose hearts could betray them at any moment. Still, people tend to underestimate how serious the problem is. Some of that is because high blood pressure has no symptoms: You don’t feel it, see it, or hear it. And for many of us, we don’t understand it and how it might affect us. Our goal today is to fix that.

And the easiest way is with the well-used but effective “garden hose” analogy. If you turn on the water and partially block the end of the hose with your thumb, the hose will bulge and the water will squirt out more forcefully around your thumb. Add a spray nozzle and you can increase the pressure enough to knock dirt off lawn furniture or loose paint off the exterior of your house. And all you’ve done is narrow the opening through which water must pass.

Your arteries are a lot like that hose, except that they form a closed loop. Blood is pumped through them from the heart, and courses through the body before returning to the heart and lungs to pick up fresh oxygen and be pumped back out again. But when blood pressure rises for whatever reason—such as narrowing of the arteries—the blood, which has no passageway out of the system, is forced up against the artery walls with increasingly brutal force.

Over time, the pressure can create bulges in the weak parts of artery walls, forcing the body to make repairs that stiffen the walls and reduce flexibility of the arteries. What’s more, as blood under pressure races through your arteries, it can knock off pieces of loose built-up plaque and detritus which can lodge in narrowed passageways, blocking the flow of blood to the heart and triggering a heart attack. Even if high blood pressure doesn’t lead to a heart attack, it causes your heart to work harder to push blood through your circulatory system. This taxes your heart muscle, causing your heart to enlarge and weaken. Eventually, the muscle may fail.

That’s the reason why your blood pressure is taken before you even see the doctor at every medical appointment. It’s that important. The exact causes of high blood pressure are still a bit of a mystery. But we do know that several factors and conditions may play a role.
• Smoking
• Being overweight or obese
• Lack of physical activity
• Too much salt in the diet
• Too much alcohol consumption (more than 1 to 2 drinks per day)
• Stress
• Older age
• Genetics
• And as we said at the start, diabetes

How to combat it? We’ll cover this in a future issue. But for now, monitor your blood pressure closely and often. Blood pressure tends to rise and fall based on continuously changing variables such as diet, stress, sleep, and activity levels. The best indicator of your blood pressure is the average of multiple screenings taken at different times of the day.

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