Blood pressure isn't calculated; it's measured. It represents the force of your blood against your artery walls. The measurement provides two numbers: systolic and diastolic pressure.
Understanding Blood Pressure Measurement
Blood pressure is measured using a sphygmomanometer (a blood pressure cuff) and a stethoscope. The procedure involves the following steps:
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Preparation: The patient should rest for at least five minutes before the measurement. They should avoid smoking or caffeine beforehand. Any tight clothing on the upper arm should be loosened or removed. [Source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3936692/]
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Cuff Placement: The cuff is placed around the bare upper arm, about one inch above the elbow crease. It should be snug but not too tight. [Source: https://www.mayoclinic.org/diseases-conditions/high-blood-pressure/multimedia/how-to-measure-blood-pressure/vid-20084748]
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Arm Position: The patient's arm should be supported at heart level. [Source: https://www.cdc.gov/high-blood-pressure/measure/index.html, https://www.heart.org/en/news/2020/05/22/how-to-accurately-measure-blood-pressure-at-home]
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Stethoscope Placement: The stethoscope is placed over the brachial artery (inside of the elbow). [Source: Figure 2 from an unspecified source - this information is implied by the given reference but the figure is unavailable]
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Inflation and Deflation: The cuff is inflated until the pulse is no longer heard. Then, the cuff is slowly deflated while listening for the return of the pulse (systolic pressure) and the point where the pulse disappears again (diastolic pressure). These two numbers represent your blood pressure reading, expressed as systolic/diastolic (e.g., 120/80 mmHg). [Source: Implied by multiple references, including https://my.clevelandclinic.org/health/diagnostics/25068-blood-pressure-measurement]
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Multiple Readings: It is recommended to take multiple readings to ensure accuracy.
Interpreting the Results
- Systolic Pressure: The higher number, representing the pressure when your heart beats. [Source: https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings]
- Diastolic Pressure: The lower number, representing the pressure when your heart rests between beats. [Source: https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings]
A blood pressure reading is usually expressed as mmHg (millimeters of mercury). Different age groups have varying normal ranges. Consult a healthcare professional for interpretation and management of your blood pressure reading. [Source: https://www.bloodpressureuk.org/your-blood-pressure/how-to-lower-your-blood-pressure/monitoring-your-blood-pressure-at-home/how-to-measure-your-blood-pressure-at-home/] For children, specific calculators exist to assess blood pressure relative to age, height, and gender. [Source: https://www.bcm.edu/bodycomplab/BPappZjs/BPvAgeAPPz.html]
