How Blood Pressure Determination helps to find and Prevent diseases?

 

Measuring blood pressure is an even more important part of the medical check today than it was in the past. For one thing, we know now how common elevated pressure is, affecting at least 17 million Americans. For another thing, we know now that high blood pressure, or hypertension, is an important factor in stroke, heart disease, and kidney disease. And best of all, hypertension today almost invariably can be controlled. Blood pressure is simply the push of blood against the walls of the arteries. It is highest when the heart contracts and pumps blood into the arteries and this peak pressure is called systolic. It is lowest when the heart relaxes between beats, and this lower pressure is the diastolic.

To measure pressure, a basically simple, though not simply named, device, the sphygmomanometer, is used. It's an inflatable cuff attached to mercury or other type of meter. When the cuff is wrapped around the arm above the elbow and inflated, the inflation does two things: it drives the mercury column up to near the top of the gauge and it compresses an artery in the arm so no blood flows through. With his stethoscope placed on the artery, the physician listens as he gradually lets air out of the cuff. At some point, as the air is released, the pressure of blood in the artery will begin to exceed the pressure of air in the cuff, and the blood will begin to flow again in the artery.

The beginning of flow produces a thudding sound the physician can hear through the stethoscope, and at this point the mercury gauge shows what the systolic pressure is. Then, as more air is released from the cuff there comes a point when the thudding sound no longer can be heard, and at this point the mercury gauge shows the diastolic pressure. It is normal for pressure to vary somewhat from day to day, even minute to minute. It goes up with excitement, which is why in an examination a physician may wish to take your pressure several times. In some people, however, the blood pressure is nearly always higher than it should be.