Is it true that blood pressure is mainly measured with the “oscillometric” technique? What does this mean?

In a doctor’s practice or hospital, blood pressure is commonly measured with the conventional “sound method”. Heartbeats are listened to with a stethoscope. These sounds in the blood stream occur in the arteries of the upper arm when the pressure in an inflated blood pressure cuff is slowly released. The first audible beat indicates the systolic blood pressure, the last audible beat indicates the diastolic pressure. Blood pressure measurements are read off a mercury column and are for that reason given as millimeters of a mercury column (mm. Hg).

Oscillometry uses a different measurement principle. Most of the presently available devices for self-measurement use this method. Electronic microprocessors in oscillometric devices calculate blood pressure from the pressure fluctuations (oscillations), which occur due to the pulses in the blood stream. As beats are not relevant in this method, neither a stethoscope nor a microphone (integrated into the blood pressure cuff) is necessary. The blood pressure and pulse rate values can be read off an optical display at the end of measurement. Although these devices do not contain a mercury column, they show blood pressure in mm Hg. With irregular pulse rates it is recommended that a doctor takes the measurement.