Diabetics, people who have higher than normal blood glucose (sugar) levels, need to keep a close eye on their glucose levels. At one time, urine monitoring was the only way to test for glucose at home, and blood tests had to be run by a laboratory. With modern home glucose monitors, tracking blood sugar makes it much easier to tailor insulin injections to current needs.
Uses
Glucose monitors are used by people with both type 1 and type 2 diabetes. Diabetics taking insulin, who need to adjust their doses according to their blood sugars, may test several times a day. People taking oral hypoglycemic (blood-glucose lowering) medications don't usually adjust their doses on a daily basis, but tracking levels helps their medical practitioners make decisions on how to adjust their medications. They may check levels once a day, once a week or less often, depending on their practitioner's instructions.
Types
Several types of glucose monitors are sold. Most take a single glucose measurement at a time, while others provide continuous glucose monitoring. Standard glucose monitors come with a device for pricking the finger, test strips and the monitor itself. Some devices designed for people with poor vision speak the results or have large numbers on the readout. Many different brands are on the market, and all have slightly different features, although all work basically the same way.
Continuous monitoring systems, which have a small sensor inserted under the skin, are good choices for people whose blood sugars are difficult to control. An alarm can warn when blood glucose is too low or high. Their cost is much higher than standard monitors.
Technique
Blood for testing is obtained by pricking the finger with a sterile needle point. Because many people are squeamish about pricking themselves, standard glucose monitors come with a device that holds a lancet, which looks like a small pushpin. After cleaning the finger with alcohol, hold the device against a finger and push a button, which pushes the tip of the pin into the fingertip. This is nearly painless. The drop of blood from the prick is directed into the test strip, which fits into the glucose meter. The meter analyzes the glucose levels in less than 2 minutes, the University of Virginia Health System reports, and displays the results on its screen.
Continuous glucose monitors have a small sensor that's placed under the skin; the device must be replaced within a week, the National Diabetes Information Clearinghouse (NDIC) states.
Accuracy
Home monitoring units are considered accurate if the results are within 15 percent of a sample drawn and run in a laboratory, the Mayo Clinic states. Several factors can give inaccurate results, including outdated strips, strips stored in an area that's too cold or hot, not enough blood on the strip and problems with the monitor itself, such as low batteries and dirt or other contaminants on the test site.
Benefits
Medical practitioners try to maintain their patient's blood glucose levels within a narrow range, as close to normal as possible, to decrease the serious damage diabetes does to small blood vessels all over the body. This requires frequent monitoring so the patient can adjust insulin, depending on his levels. Keeping blood sugars under tight control decreases stroke and heart attack by 50 percent, decreases eye damage by more than 75 percent and slows kidney damage by 50 percent, according to the Mayo Clinic.
Some devices store data and transfer it electronically so that your practitioner can have an accurate record of blood glucose readings.
Drawbacks
Glucose monitoring can be uncomfortable, because each test requires a needle stick to induce bleeding unless continuous monitoring is used. No devices on the market in 2010 tested blood glucose non-invasively, although research to develop these is ongoing. Cost is another drawback. Insurance companies vary in what they pay for monitoring devices; many pay for the unit, but the biggest expense comes from the test strips, which can be used only once and may not be fully covered.
