A glucose meter is a small, portable device designed for home use that checks glucose (blood sugar). The meter warns when blood glucose is out of range so people with diabetes can take immediate steps to correct it.

Keeping glucose close to the physician-prescribed target range can reduce or prevent the risk of diabetes complications such as damage to the eyes, kidneys, nerves and blood vessels. The meter also allows patients to monitor the effects of diet, exercise, stress and medications on glucose levels.

The meter reads a blood sample taken from a fingertip, arm, hand, abdomen, thigh or calf. It digitally displays the glucose level as a number in milligrams per deciliter (mg/dL) that can be recorded for glucose monitoring. Patients and their physicians can review the results and decide if the diabetes care plan is working. Some diabetic patients, particularly those who use insulin, need to test more than others. A glucose testing schedule should be designed for each individual patient by a physician.

Dozens of meters are available on the market. Models vary in size, speed, cost and ease of use, and they each have their own set of features. In choosing a meter, patients should consider the advantages and disadvantages of different models and ask their physician for advice on what meter is right for them. There have been many recent innovations, including a combination insulin pump and glucose meter that monitors glucose continually.

Accurate readings are essential for management of glucose. Mechanical and human error can cause inaccuracy. Glucose meters have various controls patients use to standardize the readings, including glucose control solutions and electronic meter controls.

Patients are advised to bring their glucose meter with them on diabetes appointments. When a meter reading is recorded a few minutes before blood is drawn for laboratory tests the results can be compared for accuracy. The physician can also view the patient’s testing method to ensure that self-tests are being completed properly.

Other glucose testing methods exist, including the glycohemoglobin test, but the glucose meter is the most accurate home method for assessing day-to-day glucose control. Researchers are developing noninvasive monitoring techniques.