How Blood Pressure is Measured
The most familiar way of measuring blood pressure is using a cuff that expands with air and a stethoscope. The cuff is expanded to briefly cut off the flow of blood. A medical professional, places a stethoscope on the inner surface of your elbow and opens the valve to slowly release air from the cuff. As your blood begins to flow back through your arm it makes a pulsing sound. Your provider listens with a stethoscope for this sound.
When the first sound of the pulse is heard, the number from the pressure gauge is recorded. This is your systolic blood pressure. It represents the pressure in your arteries when your heart contracts (beats). When the sound fades, that number is recorded from the pressure gauge. This is your diastolic blood pressure. It represents the pressure of the blood in your arteries when your heart rests between beats.
Blood pressure is written as systolic over or before diastolic e.g. 120/80. Again, 120/80 is considered “normal”.
|Systolic (Top #)||Diastolic (Bottom #)||Rating|
|120 or below||and 80 or below||Normal|
|120 – 139||or 80 – 89||Pre-hypertension|
|140 – 159||or 90 – 99||HBP (stage 1)|
|160 or higher||100 or higher||HBP (stage 2)
If you have diabetes or chronic kidney disease, HBP is defined as 130/80 or higher.
Here is the tricky thing about figuring out whether your blood pressure is high. If your systolic blood pressure is 110, but your diastolic blood pressure is 92, it’s in the normal range for systolic but high for diastolic so, you have stage 1 HBP. Likewise, if your diastolic pressure is 80, but your systolic pressure is 160, you have stage 2 HBP. So, in other words, if any of your numbers fall into an abnormal level, then you have HBP in the high range of the reading.