Test Strips
The simplest parts of a glucometer are the test strips, which are designed to pick up a consistent amount of blood and then to deliver it to the glucose meter. In general, using a glucometer involves putting one of these strips into the glucometer and then pricking your finger. Once you place a drop of blood on the other end of the strip, it uses a phenomenon called capillary action to move the blood to the glucometer. Capillary action occurs when a liquid is able to spontaneously travel up a very thin tube without any energy being required. The test strips make use of capillary action to move a precise amount of blood onto the glucometer.
Glucometer
Glucometers have two different ways of measuring the amount of sugar that's present in the blood. Both methods involve the use of enzymes, which are special proteins that can cause chemical reactions. The test strips in glucometers have enzymes that react with the glucose in the blood. Sometimes this chemical reaction causes a color change, which the glucometer measures and translates into a glucose concentration (typically given in milligrams per deciliter). Other systems use a series of enzymes to cause glucose to react in such a way that a small amount of electricity is produced. In this case, glucometers translate this electrical activity into a glucose translation.
Other Features
Most glucometers use a digital readout that displays the blood glucose reading in miligrams per deciliter. Many modern glucometers also have software included that monitor and track changes in blood glucose over time. Others simply store the last several readings, allowing a patient to manually keep track of blood glucose levels over time. Most meters also have a "LO" or "HI" reading for blood glucose levels that are below or above what the machine can accurately detect.
