Accurate Blood Pressure Measurement: Why do monitors read high?

If you have ever used an automated monitor to measure blood pressure, you probably have encountered a reading you thought was too high. In these situations, clinicians usually take a measurement themselves using a sphygmomanometer and stethoscope to either confirm the reading or question whether the monitor is working properly. If the reading is confirmed, you and your patient may be surprised to realize that your patient’s BP is not what you expected. Alternatively, if the reading is different, you may wonder if your monitor is calibrated or operating correctly. Regardless of the situation, why is this happening at all?