Fortunately for the 37 million Americans with diabetes, technological advances, particularly over the past several decades, have made monitoring blood glucose (blood sugar) easier. Blood glucose meters (BGMs) continue to play an important role in diabetes management. Understanding how they work is essential for your best diabetes self-management and to prevent or delay complications.

Accuracy and Use of Blood Glucose Meters 

BGMs provide accurate blood glucose (blood sugar) readings. In fact, the Food and Drug Administration (FDA) requires all BGMs to be accurate within about 15–20% above or below the actual reading. BGMs are small portable devices with a screen and display your results in seconds. They measure blood glucose levels using whole blood and a test strip. Most people use the end of their finger as the primary testing site—which provides a reading with no delay.  

BGMs can be the only device you use to track your blood glucose or may serve as a backup option to a continuous glucose monitor (CGM). For example, a BGM can be used to confirm a hypoglycemia (low blood glucose) reading from your CGM, like in this personal testimonial from a CGM user:

"I woke up in the middle of the night to my CGM warning me about a severe low blood glucose. It said I was in the 40s and trending down, which surprised me as I usually wake up on my own when my blood glucose starts to go low. Besides being groggy and sleepy (which wasn’t surprising as it was 3:00 a.m.), I didn’t have any of my usual symptoms of low blood glucose.

Skeptical, I got up and decided to check the CGM reading against that of my handheld blood glucose meter. To my surprise, my handheld glucose meter confirmed that I was indeed having a severe low glucose reaction and that my blood glucose level was already into the 20s. Upon seeing that reading, I immediately woke up my husband as a precaution and got a snack.

It was a jarring experience overall, and I was grateful my CGM woke me up and that I had my handheld blood glucose monitor nearby to double check my numbers."

 

What to Be Aware of with Blood Glucose Meters

Here is information to be aware of regarding BGMs:

• It’s important to check the expiration date of your test strips. A test strip’s ability to generate an accurate reading weakens after the expiration date. 
• Store your BGM and test strips at room temperature and in dry spaces.
• Although most CGMs do not need calibration, some may require a BGM to calibrate the device.

Accessibility and Affordability of Glucose Monitors and Meters

Most insurance companies cover BGMs and test strips for their beneficiaries with diabetes. Depending on your insurance, there may be cost sharing and coverage limitations. Blood glucose monitoring is a very important part of diabetes management though, so be sure to discuss which options are the most appropriate for you with your health care provider. 

Other Ways to Measure Blood Glucose

CGMs

CGMs, which use sensors on the skin, continually measure blood glucose levels and notify those who wear them if they are trending low or high so they can take corrective action. There may also be cost sharing and coverage limitations for CGMs depending on your insurance plan.

A1C Test

Beyond daily glucose checks with a CGM or BGM, another way your blood glucose (blood sugar) is measured is through an A1C test. An A1C test is a blood test that gives you a picture of your average blood glucose over the past two to three months. This test can show how well your diabetes treatment plan is working and helps your health care provider recommend changes to your diabetes management plan. Plan to get an A1C test every six months or more often, as recommended by your health care team.

A1C test results are given as a percentage and can be translated into mg/dL like your BGM and CGM. The American Diabetes Association recommends most non-pregnant adults with diabetes aim to have an A1C level of less than 7% or 154 mg/dL. This target can be different for each person based on a variety of factors, so talk to your health care provider about what your own A1C goal should be. 

While an A1C test paints a broad picture of how well your diabetes treatment plan is working, CGMs or BGMs provide you with ongoing, daily readings to help you manage your diabetes day to day. 

The Takeaway

There are a lot of factors to consider when determining which blood glucose monitoring method is right for you. Talk to your health care provider to determine what’s best for your lifestyle and treatment regimen.