How does a sphygmomanometer work?« Back to Questions List

Sphygmomanometers are used for measuring blood pressure. Our heart pumps blood to all parts of the body. The blood pressure measurement is done to check if the heart and the pipes which carry the blood are working fine.






The normal reading of blood pressure is 120/80. These two numbers indicate what is called the systolic and diastolic pressure. The blood pressure reading is taken by first tying a cuff around the arms. Now air is pumped inside the cuff so that it presses on the arm stopping the blood flow. As the pressure on the cuff is slowly released, blood starts flowing again. The first reading (120 mm Hg) is the measure of maximum output pressure of the heart and is called the systolic pressure. The other reading (80 mm Hg) that is taken finally is when blood flows normally or the pressure at which heart pumps when relaxed. This is called diastolic pressure.


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When the blood pressure readings are not quite close to the normal reading (120/80), it indicates either the heart is not working properly or that the arteries (carriers of blood) are not working properly due to blockage or that they have become thin. In any case, it puts more pressure on the heart to pump blood. Constant stress could also result in higher blood pressure which again results in malfunctioning of the heart resulting in fatal heart attacks.



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