Here's a step-by-step explanation of how a blood pressure gauge works:
1. Preparation: The person's upper arm is exposed, and the cuff of the blood pressure gauge is wrapped snugly around the arm, about 2-3 centimeters above the elbow crease.
2. Inflation: The bulb of the gauge is squeezed to inflate the cuff, increasing the pressure inside the cuff and compressing the brachial artery below.
3. Listening for Korotkoff Sounds: The person taking the blood pressure (usually a healthcare professional) listens with a stethoscope placed over the brachial artery, just below the cuff. As the cuff deflates, certain sounds called Korotkoff sounds can be heard.
4. Systolic Pressure: The first Korotkoff sound that is heard is the systolic blood pressure. It represents the maximum pressure reached during a heartbeat when the heart contracts and pumps blood out to the body.
5. Deflation: The cuff is slowly deflated while the healthcare professional continues listening through the stethoscope.
6. Diastolic Pressure: The point at which the Korotkoff sounds disappear is the diastolic blood pressure. It represents the lowest pressure in the arteries during the heart's resting phase, before the next contraction.
7. Recording the Results: The blood pressure reading is recorded as two numbers: the systolic pressure (higher number) and the diastolic pressure (lower number), separated by a slash (for example, 120/80 mmHg).
It's important for the healthcare professional to follow proper techniques and guidelines to obtain accurate blood pressure measurements. Factors like the correct cuff size, proper positioning of the cuff, and avoiding movement or talking during the measurement can influence the accuracy of the results.
