By Timothy Aungst
If you have type 2 diabetes, your healthcare provider may recommend that you monitor your blood sugar at home to make sure you’re within your target range. Regularly checking your blood sugar can be valuable, but you may have questions about what device to use and what your numbers mean. Here, we’ll look at the options and walk through how to interpret your results.
First, who should monitor their blood sugar at home?
Not everyone with diabetes needs to monitor their blood glucose at home. However, under a few conditions, your provider may feel that it’s worth considering:
- If you are taking medications that can cause your blood sugar to fluctuate drastically, such as insulin or certain non-insulin diabetes medications
- If you are pregnant
- If you tend to experience low blood sugar (hypoglycemia)
- If you have a hard time reaching your goal blood sugar levels
How can measuring my blood sugar help?
Monitoring your blood sugar at home supports your overall diabetes treatment plan. Your provider will measure your blood sugar when you visit their clinic, but at-home monitoring will give you and your provider a record of how your blood sugar changes outside of those visits. This gives you both an idea of what to do next.
For example, if you notice that your blood sugar spikes at certain times of the day (like after you eat a large dinner), you’ll know when to take your insulin. Or maybe you experience hypoglycemia after taking too much insulin. This could be a clue that you need to reduce your insulin dose. As you and provider adjust your dose, or maybe change your medications, home blood sugar measurements can give you an idea of whether your treatment is working or if you need to continue adjusting it.
Blood glucose monitors: What are my options?
There are many devices on the market that can help you check your blood glucose, but they generally fall into 2 categories:
- Self-monitoring blood glucose (SMBG) devices. With SMBG devices, you test your blood sugar multiple times a day, each time pricking your finger and testing a drop of blood with a test strip. Many of these devices can store your results over time. Some newer ones even allow you to send your results to your smartphone through an app. Popular SMBG devices include OneTouch Ultra 2, Coaguchek XS, and Contour Next.
- Continuous glucose monitoring (CGM) devices. In contrast to SMBG devices, CGM devices measure your blood sugar at regular intervals throughout the day. Popular CGM devices include Freestyle Libre 14 day, Dexcom G6, and Medtronic Guardian Sensor 3. These tend to be newer than SMBG devices and feature an adhesive patch with a small microneedle sensor that you attach to your skin (usually on your belly or arm). The sensor measures your blood sugar and sends your results to an app on your smartphone or another device you carry around with you. Some CGM devices come attached to insulin pumps that give you insulin when your blood sugar is high.
How do I use a blood glucose monitor?
If your device is new to you, ask your healthcare provider to show you how to set it up and use it. Below are some basic guidelines.
Self-monitoring blood glucose devices
SMBG devices come with the same general instructions. To use one properly, you’ll need a few supplies:
- The SMGB device that your provider prescribed to you
- A corresponding test strip (each device has its own specific test strips)
- Alcohol wipes
- A lancet
- A sharps container for when you dispose of your lancet
Start with washing your hands with soap and water. Allow your hands to air dry. Then, wipe the finger you will draw blood from with an alcohol wipe to prevent an infection.
After that, prick the tip of your finger with a lancet to draw a little blood—and don’t forget to safely dispose of your lancet in your sharps container. The center of your finger has more nerve endings than the sides, so pricking the side of your finger might be less painful. Also note that each monitor may need a different amount of blood. Be sure to read the manual for details.
Once you’ve inserted a new test strip into your monitor, touch the appropriate edge of the test strip to your blood and wait as your device reads the sample and displays your results.
Continuous glucose monitoring (CGM) devices
The setup process for CGM devices will differ depending on which one you are prescribed. For the best results, have your provider or pharmacist show you how to set it up.
Some CGM devices require you to check the device’s accuracy a couple times a day. To do this, you’ll need a standard SMBG device. You’ll test a drop of blood on both devices, and if the CGM is accurate, both devices will display similar results.
CGM devices also have an adhesive sensor that will generally need to be replaced over time. It will vary depending on the product, but many can go without a new sensor for as long as 14 days. These sensors can now be synced to your smartphone via an app or with another device that tracks your sugar levels. Everytime you reapply a new sensor, you will need to resync it for data collection.
What do the numbers mean?
Now the challenging part: How do you know if you blood sugar numbers are good or bad?
First off, it’s important to know that everyone will have different blood sugar goals. Your provider should let you know what numbers you need to aim for. Your goal range will depend on multiple factors, including your health and age, the medications you take, and how far your diabetes has progressed.
Second, your numbers will change depending on what and when you eat. Your numbers will rise after eating and will gradually go down after you finish eating. The American Diabetes Association recommends that most people have a blood sugar reading of 80 mg/dL to 130 mg/dL before a meal, and less than 180 mg/dL 1 to 2 hours after a meal. But this is also one of the reasons why most providers use a hemoglobin A1C test on top of your at-home blood glucose tests. A1C is a measure of your average blood glucose over the past 2 to 3 months.
Which type of device is right for me?
CGM devices are probably more convenient. Unlike SBMG devices, CGM devices don’t require you to remember to test your blood sugar multiple times a day. They also don’t need you to prick your finger, so they can be less painful.
If you feel like SBMG devices are a hassle, talk to your provider about getting a CGM device. They’ll want to help, especially if it makes you more inclined to monitor your blood sugar regularly.
When it comes to cost, insurance coverage can be a concern for some patients. Insurance plans will generally cover a few SMBG devices. (If you’re counting on your insurance, be sure to check that the one you buy is covered so you’re not hit with sticker shock when you get to the pharmacy.) CGM devices, on the other hand, are newer to the market so fewer insurance plans tend to cover them.
And if you don’t have insurance or the SMBG device you want is too expensive for you, know that there are ways for you to save—or even get them for free. See here for information on savings programs for SMBG monitors and test strips.
The bottom line
Not everyone needs to an at-home blood glucose monitor, but if your provider feels that it can help you reach your goals, then you have many devices to choose from. SMBG and CBG devices offer different advantages and disadvantages. Ask your provider or pharmacist for help if you need any guidance on how to choose and get started with monitoring your blood glucose at home.