Measuring Your Blood Pressure

A sphygmomanometer is used to measure blood pressure. An airtight cuff is wrapped around the arm just above the elbow. The cuff is connected to a glass tube filled with mercury. Air is pumped into the cuff by squeezing a bulb. As the cuff becomes tighter, it compresses a large artery in the arm -- the brachial artery. This temporarily cuts off the flow of blood to the forearm, and no heart sounds can be heard when a stethoscope is placed on the compressed artery just below the cuff. As the air pressure in the cuff is released, the mercury level drops. Eventually, a point will be reached at which the blood pressure in the artery is just greater than the air pressure in the cuff. Blood will now begin to flow through the artery, and the heart sound may be heard through the stethoscope. This is the systolic, or upper, pressure; it is the maximum pressure that can be produced by the heart. As air continues to be let out of the cuff, the sounds heard through the stethoscope will become louder as more blood flows through the artery. Finally, a point will be reached at which the distinct heart sound disappears as the blood is flowing steadily through the artery. At this point the height of the mercury shows the diastolic, or lower pressure, representing the least amount of pressure in the artery.

Results

Record your blood pressure figures in the space provided below.

Interpretation

Your blood pressure scores can be evaluated by consulting Table 3-4, below.