What is a Blood Glucose Meter?
A glucose meter is used to test a small blood sample to check the glucose (sugar) level in your blood. Hypoglycemia happens when our sugar level is around 70 milligrams per deciliter (mg/dl) or below. There are various reasons glucose levels may fall, like exercise, medications, foods, fasting, stress, and more. It’s important for people who have diabetes or hypoglycemia to know what their sugar levels are, as it can be very dangerous when glucose levels aren’t stable.1
How is Blood Sugar Measured?
A doctor can have your blood tested in a lab, called the A1C test. This blood test will show what your average blood sugar has been for the past 2 to 3 months. The other test method is by using a glucose meter. This testing method is done at home and gives a reading of your blood sugar level at the time of testing. 2
Blood glucose monitoring devices help bring peace of mind. They give us the ability to test at home and know what our sugar levels are, thus making it easier to manage balanced levels with food or medication. If glucose levels go too high or too low, there can be very serious physical issues which might be life-threatening.1
Testing yourself at home regularly will help you know what your blood sugar levels are, and it will be easier for you to make adjustments in treatment. A blood glucose monitor will let you know if your levels are high or low, and if there’s cause for concern. By testing at different times of the day, after meals or exercise, you’ll begin to understand how your sugar levels are affected. Monitoring your glucose levels on a regular basis will lead to better health and fewer complications.1
How to Use a Glucose Meter
First off, make sure to read the instructions for your meter and test strips. After inserting a new strip into the glucose meter, shake your hands beneath your midsection or heart, and rub the finger you have in mind of using to get your blood flowing. Swab your finger with rubbing alcohol or wash your hands with warm water and dry them off.3
Prick your finger with the lancet, (a type of needle), to produce a drop of blood. The lancet is fast and easy, so the process is over quickly. Once you have a drop of blood, you’ll touch it to the end of a disposable test strip. The strip will soak up the blood, and the chemicals on the strip will react with the glucose, the results will showing on the screen. Glucose meters in the U.S. give results in milligrams or glucose per deciliter of blood, mg/dl.1
Learn what “high” and “low” means on the display of your meter. If your sugar level exceeds the high or low range, that’s measurable by the meter, a “LO” or “HI” may show on the display.4 If your glucose levels are too high or too low, this is cause for alarm and you should do what is necessary to balance them out again. For instructions on bringing sugar levels up when they are too low, click here to go to my treatment page. Call your doctor if you desire medical counsel.
If you feel unsure about using your meter, ask your doctor or someone who uses one to show you how to operate the device. Whenever you test with your meter, use a new test strip every time. The strip should slide into the meter and stop once it reaches the end of the meter guide.5 It’s a good idea to keep your glucose meter with you at all times as this will help you manage your levels.3
Methods to Increase Accuracy
There are several things you can do to improve the accuracy of the reading that your glucose meter produces. Before checking your blood, make sure your hands are clean and dry.5 Not drying your hands can alter the results if water combines with your blood. And if there is any kind of sugary coating left on your testing finger, the meter can end up with a high reading.6
After pricking your fingertip, do not squeeze your finger, allow the blood to flow freely. Be certain the drop of blood is enough to test with, otherwise the meter may not read the glucose well. Sometimes an error message will appear if the blood sample is too small. This error message isn’t reliable as it doesn’t always pop-up and can leave you with an incorrect reading. Retest if you’re ever unsure.5
Meters are different in how much blood they require to test on a strip. What’s needed can range from a general small drop of blood to a drop the size of a pinhead. (Check the manual instructions for the exact amount.)7
Here are other factors that may affect the accuracy of test;
- Quality of the meter and test strips being used
- Not following the operating instructions of the meter
- Vitamin C, Tylenol, and uric acid in your blood
- If you’re severely dehydrated or anemic
- If the meter and strips are not properly stored in closed vials
- Using expired test strips or storing them in a broken bottle
- High altitude, low and high temperatures, or humidity1
- Not using the correct test strips meant for your particular meter4
- If you have a high red blood cell count (hematocrit)5
- Your blood sugar is too low5
Even though test strips look very similar, they’re not identical and can be a particular size or have distinct chemical coatings. It’s possible a test strip that’s not meant for your meter will fit into the device, but this can produce incorrect results.5 Double check that the code on the strip container is the same as the code on the device.6
Meter’s with different prices or design options can vary in accuracy. Since there are many things that can affect glucose readings, it’s best to decide which to buy based on the operating features you find important.7
The Food and Drug Administration (FDA) sets accuracy guidelines for glucose meters advertised in the U.S., based on recommendations by the International Organization for Standardization (IOS), which establishes worldwide product standards.7
Meter accuracy guidelines:
For results that are 75 mg/dl or higher:
- 95% of glucose meter test results have to be within plus or minus 20% of the actual blood glucose level.
- For instance, if the actual blood glucose result is 180 mg/dl, the meter might display a reading ranging anywhere from 144 mg/dl to 216 mg/dl and still be within the guideline standard.8
For results under 75 mg/dl:
- 95% of glucose meter test results have to be within plus or minus 15% of the actual blood glucose level.
- If the actual blood glucose result is 70 mg/dl, the meter might display a reading ranging from 55 mg/dl to 85 mg/dl and be within the guideline standard.8
To test the accuracy of a meter, it’s done in a controlled laboratory setting with good quality equipment. Doing this provides an ideal setting with no errors, which means the meters meet ISO standards used to determine if a meter is advertisable in the U.S. When people use glucose meters, there are many things that can affect the accuracy. Following the directions for your meter, re-testing and testing often will provide a good range of blood sugar readings for you to use as a guide to good health.8
After meters and test strips are sold on the market, the FDA no longer focuses much attention on the products. Companies that sell meters and strips are not held accountable in keeping up with a comparable standard of accuracy. Physicians and the public help contribute to maintaining the quality of devices and strips by alerting the FDA with reports of complications while using their devices. The FDA may then administer a recall on certain products and educate the public with new information about concerns for particular devices or test strips.7
Deciding Which Glucose Meter is Right For You
When choosing a glucose meter, there are lots of things to consider. Devices available on the market can vary and it’s important to put thought into which one you buy.
Things to consider when purchasing a glucose meter and how they operate;
- Accuracy of the device. (Some are very accurate, while others are not reliable.)
- The amount of blood needed for testing
- How easy the device is to use
- Is it a minor prick or more painful to collect a blood sample?
- Testing speed
- How big the glucose meter is. (You may want a small one so you can easily carry it along with you wherever you go, or a larger one if you have visual difficulties and need to better see the buttons and screen.)7
- Does it come with a pouch to store it in?1
- Does the meter have memory to store test results?
- Likelihood of interference by factors that can affect accuracy
- Can the meter transmit data to a computer or device? (Looking over data could show you and your doctor patterns, which is a helpful guide in making life adjustments to improve health.)7
- How much does the meter cost? How much do more test strips cost?
- Does the manufacturer offer technical support if you have operating issues?
- Are there any special features, like automatic timing, error codes, a large display screen, and does the screen light up? Is there audio with spoken instructions or results?1
Pricing for devices and test strips can differ as there are many types of glucose meters available to buy. They range from basic to advanced, and cost may not make any difference in the accuracy of the device. Check with your insurance company to see if they offer any coverage for glucose meters. Some companies are particular, covering only certain models and may have a limit of the overall number of test strips permitted.9
To read a review for the Best-Selling, Highest-Rated Glucose Meter Kit sold on Amazon, Click Here.
Troubleshooting Your Device
To ensure your glucose meter is operating well;
- Do electronic checks. When you turn the meter on, it does an electronic check to scan for issues. An error code will appear if the meter detects a malfunction. If this happens, look through the manual for the device on information about error codes and how to fix them. If you’re concerned about whether your glucose meter is functioning as it should, call the toll-free number found in the device’s manual, or contact your doctor.1
- Bring your glucose meter along to a doctor’s appointment. Show your physician how you use the meter so they can suggest tips in altering your technique.1
- Ask to have your blood tested in a laboratory. Look at the blood glucose readings from your meter and compare those to the results of the test done in the laboratory. If the readings are similar, then you know your meter is fine and you’re using it properly.1
- Use liquid solutions
Use liquid control solutions when;
- Opening a new test strip container
- At different times as you use the test strips
- If the meter is dropped
- The meter gives abnormal results1
When testing a liquid control solution, a drop of solution is added to a test strip and the glucose meter tests the solution, as it would a drop of blood. The reading should be the same as indicated on the label of the test strip vial. Most glucose meters come with this solution.1 Shake the bottle before using. After opening the solution, it will expire within three months, so write the date it was opened on the container.6
Regular Maintenance of Your Blood Glucose Meter
- Look at the manual for your device to learn how to clean and disinfect the meter.4
- Use the control solution to test the accuracy.
- When you take a test strip out of the bottle, close the cap right away.
- So as not to damage the strips or device, keep everything stored away from heat and humidity.
- Having extra batteries on hand is also a good idea. 5
Alternative Site Testing
Blood samples from other parts of the body
Your fingertips are the most accurate location for testing glucose. Certain meters can test from other areas of your body, known as alternative site testing or AST. The various locations are; palm, upper arm, forearm, thigh, or calf. AST may produce inaccurate results when your blood glucose is changing quickly,1 as it can take around 20 minutes to show changes in blood sugar.7 Therefore, use your fingertips if your sugar levels are changing and only consider an alternative site test when your glucose is steady.1,7
Glucose can change very fast when;
- You’re unaware you’re having symptoms of hypoglycemia, (unawareness).
- Your blood sugar is low
- You’ve taken insulin
- The glucose meter results don’t line up with how you’re feeling.
- You just ate food or exercised
- You’re sick or stressed1
Discuss alternative site testing with your doctor as this may not be a good solution for everyone. Remember, only certain meters can test from alternative sites.5To connect with a physician, click here to go to my review on HealthTap.
Understanding Blood Glucose Readings and Knowing When to Test
How often you check your glucose depends on your personal circumstances. Your doctor may recommend testing several times throughout the day. If you sense your sugar levels going high or low, definitely test for a reading. Activity level, the foods you’re eating, and stress factors will all affect your levels. Checking multiple times can help you make any necessary adjustments to your diet or treatment. This is something you’ll want to discuss with your doctor.1
Normal Blood Glucose Levels
Below is a list of the recommended times to test and the ranges for blood glucose levels for those times;
|Good Times to Check Blood Glucose||People Without Diabetes||People with Diabetes or Hypoglycemia (Under 70)|
|Before Breakfast (Fasting)||Less than 100||70-130|
|Before Meals (Lunch, Snacks, Dinner)||Less than 110||80-130|
|2 Hours After the Start of a Meal||Less than 140||Less than 180|
|Bedtime||Less than 120||90-150 10,2|
After testing, keep a blood sugar record by writing in a journal or logging in your meter (if the device has this option) the date, time, and glucose reading. (Some meters will automatically do this.) For future appointments with your doctor, bring your blood glucose record and meter along to discuss the information.2
Caution Concerning Pre-Owned
According to the FDA, some merchants are selling pre-owned or secondhand test strips to consumers. These strips are unused, but previously owned by another person, and can be cheaper than new strips. Sellers may advertise low-priced test strips on the internet or by using flyers in neighborhoods.4
It is legal to resell test strips, but the FDA discourages against buying pre-owned strips or reselling your own unused test strips. The reason being is that pre-owned strips are not reliable in giving accurate results. You don’t know if they were stored properly or expired. Someone may have opened the test strip vials and there could be blood on them, which may give you an infection. Cheap strips could be altered by the seller, (expiration dates changed or covered up).4
Pre-owned strips may not be FDA approved to be sold in the U.S. Instructions not printed in English or strips with a different appearance compared to other test strips of the identical brand are indications they are not safe for use. Using these types of strips can give you readings that are wrong, which could leave you with severe health complications or the risk of death.4
In most cases, blood glucose meters are reliable as a tool to help monitor your blood glucose levels. It’s important to understand that they are not flawless. The most accurate testing is done at the hospital or in a doctor’s office.5 As you take steps to care for your health, it can be very helpful to have data that shows a range of readings over a period of time.8 These types of meter’s make it easy to test your sugar levels from the comfort of your home, and they give you the ability to check your levels at any time.
Please feel free to leave a comment down below!
What are your thoughts or concerns? Do you have personal experience using a glucose meter or know someone who does? If you currently use a meter, do you think its helped you keep track of your glucose levels?
Published May 24, 2017
1) Blood Glucose Monitoring Devices. U.S. Food and Drug Administration. https://www.fda.gov/medicaldevices/productsandmedicalprocedures/invitrodiagnostics/Glucosetestingdevices/default.htm. Updated December 22, 2016. Accessed May 22, 2017.
2) Know Your Blood Sugar Numbers: Use Them to Manage Your Diabetes. The National Institute of Diabetes and Digestive and Kidney Diseases Health Information Center. https://www.niddk.nih.gov/health-information/diabetes/overview/managing-diabetes/know-blood-sugar-numbers. Published March 2016. Accessed May 20, 2017.
3) Blood Glucose Testing Delivers Tight Control. Joslin Diabetes Center. http://www.joslin.org/info/blood-glucose-testing-delivers-tight-control.html. Accessed May 21, 2017.
4) How to Safely Use Glucose Meters and Test Strips for Diabetes. U.S. Food and Drug Administration. https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm049051.htm. Published March 18, 2008. Updated May 16, 2017. Accessed May 20, 2017.
5) Home Healthcare Medical Devices: Blood Glucose Meters – Getting the Most Out Of Your Meter. U.S. Food and Drug Administration. https://www.fda.gov/medicaldevices/productsandmedicalprocedures/homehealthandconsumer/ucm070212.htm. Updated March 25, 2015. Accessed May 19, 2017.
6) Little Things that Can Have a Big Impact on your Blood Glucose Reading. Joslin Diabetes Center. http://www.joslin.org/info/little_things_that_can_have_a_big_impact_on_your_blood_glucose_reading.html. Accessed May 22, 2017.
7) Tsai, A. Meters: Does Your Device Measure Up? What to look for when buying a blood glucose meter. Diabetes Forecast: The Healthy Living Magazine. http://www.diabetesforecast.org/2015/mar-apr/meters-does-your-device-measure-up.html. Published March 2015. Accessed May 22, 2017.
8) Blood Glucose Meters 2013. Diabetes Forecast: The Healthy Living Magazine. http://www.diabetesforecast.org/2013/jan/blood-glucose-meters-2013.html. Published January 2013. Accessed May 21, 2017.
9) Mayo Clinic Staff. Blood glucose meter: How to choose. Mayo Clinic. http://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/blood-glucose-meter/art-20046335. Published December 17, 2016. Accessed May 19, 2017.
10) Goals for Blood Glucose Control. Joslin Diabetes Center. http://www.joslin.org/info/Goals-for-Blood-Glucose-Control.html. Accessed May 20, 2017.