What tool is commonly used to measure blood glucose levels?

The tool commonly used to measure blood glucose levels is a glucometer. This device is specifically designed for this purpose, allowing individuals, particularly those with diabetes, to monitor their blood sugar levels accurately and conveniently. A glucometer typically requires a small drop of blood, which is obtained by a quick fingerstick, and then displays the blood glucose level on a digital screen.

In contrast, other options such as the sphygmomanometer, pulse oximeter, and thermometer serve different functions. A sphygmomanometer is used to measure blood pressure, while a pulse oximeter measures the oxygen saturation of a person's blood. A thermometer is used to assess body temperature. Each of these tools is vital in medical settings, but they do not measure blood glucose levels like a glucometer does.