Table of ContentsView AllTable of ContentsHow They WorksTypes of CGMsBenefitsLimitationsCostWho Uses CGMs
Table of ContentsView All
View All
Table of Contents
How They Works
Types of CGMs
Benefits
Limitations
Cost
Who Uses CGMs
Managing diabetes can now be done with blood sugar monitors that don’t require a finger prick. A variety ofcontinuous glucose monitors (CGM)can accurately check your blood sugar throughout the day via a small sensor inserted under the skin.
The sensor is usually not even detectable once it’s placed, and since it constantly measures internal glucose levels, you don’t need to prick your finger to get a blood sample. Although, some devices may require a finger prick to initially calibrate the device.
These monitors are useful for people who havetype 1 diabetesortype 2 diabetes, especially those who takeinsulin. Different types of CGMs are appropriate for different needs.
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How Continuous Glucose Monitors Work
While some of the features of various CGMs differ, they all consist of the same basic system that allows them to measure real-time sugar levels.
These monitors usually consist of three parts:
Depending on the exact device, your sensor might be inserted in your abdomen or arm. An adhesive patch goes over the skin to hold the sensor and transmitter in place.
After the sensor is placed, it may take some time (30 minutes to two hours) for the system to warm up or calibrate. Some devices require you to do a finger prick at this point so it can set up an accurate starting reading.
You can usually set various alerts or personalized ranges on the monitor. The device will alert you (with a sound or vibration) when glucose levels aretoo highortoo low. It will also notify you when the sensor needs to be replaced.
Tracking Your Sugar IntakeSome CGMs allow you to record food and beverages you consume so you can better manage your diabetes. You may also be able to track physical activity and medications, all of which affect your blood sugar.
Tracking Your Sugar Intake
Some CGMs allow you to record food and beverages you consume so you can better manage your diabetes. You may also be able to track physical activity and medications, all of which affect your blood sugar.
Types of Sugar Monitors Without Finger Pricks
There are two broad categories of continuous glucose monitors:
Brands of CGM
The best type of CGM depends on your individual needs. These are some of the popular devices available today.
Over-the-Counter CGMsThe Food and Drug Administration (FDA) has approved one continuous glucose monitor that’s available over the counter without a prescription.The Dexcom Stelo Glucose Biosensor Systemis for adults with diabetes who don’t use insulin.
Over-the-Counter CGMs
The Food and Drug Administration (FDA) has approved one continuous glucose monitor that’s available over the counter without a prescription.The Dexcom Stelo Glucose Biosensor Systemis for adults with diabetes who don’t use insulin.
The Food and Drug Administration (FDA) has approved one continuous glucose monitor that’s available over the counter without a prescription.
The Dexcom Stelo Glucose Biosensor Systemis for adults with diabetes who don’t use insulin.
Continuous glucose monitors have become increasingly easier to use and the readings more accurate over the past few years. Arm systems now offer accuracy of up to 95% and abdomen devices are up to 93% accurate.
CGM devices test the fluid in the space around the body’s cells, which is just as effective for glucose monitoring as blood from capillaries (small blood vessels, such as in your fingertip).
Other advantages of CGMs over traditional fingerprick monitoring include:
Limitations of Continuous Blood Sugar Monitors
While CGMs are convenient and can monitor blood sugar without finger pricks, they do have some drawbacks.
The first concern is that the results may be inaccurate. For this reason, it’s recommended that if you get an alert that your blood glucose is too high or too low, you should verify the level with a finger prick blood test before you take actions such as increasing your insulin dose.
Other issues with CGMs include the following:
Cost of Continuous Glucose Monitors
Without insurance, you may pay between $2,500 and $6,000 annually for CGM.The starting price for glucose monitoring devices is $220 per month with prices for other devices ranging from $1,000 to $1,400 and replaceable sensors costing $35 to $100 every seven to 10 days. Replacement batteries cost about $500 per year.
However, manufacturers offer coupons and savings programs to reduce the cost for those without insurance.
Who Should Use Blood Sugar Monitors Without Finger Pricks?
These devices are also effective for people with type 2 diabetes who aredependent on insulin.
In addition, healthcare providers may recommend CGMs for other conditions that impact glucose levels, like:
FDA Warning About Phone AppsThe FDA has issued a warning regarding smartwatches and phone apps that claim to be able to measure blood sugar. These applications, which are not connected to sensors in the body, do not accurately measure blood glucose values.
FDA Warning About Phone Apps
The FDA has issued a warning regarding smartwatches and phone apps that claim to be able to measure blood sugar. These applications, which are not connected to sensors in the body, do not accurately measure blood glucose values.
Summary
Continuous glucose monitors are blood sugar monitors that do not use finger prick tests to measure glucose throughout the day. A sensor inserted or implanted into the arm or abdomen sends regular readings of glucose to a monitor. If your blood sugar is too high or too low, an alert goes off, or an automatic insulin injector may be triggered.
These monitors are convenient and avoid the pain of constant finger pricks. There are some downsides to the system, but for many people, they prove to be easy to use and may help you manage your diabetes.
17 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Diabetes and Digestive and Kidney Diseases.Managing diabetes: continuous glucose monitoring.American Association of Clinical Endocrinology.CGM device comparison.Food and Drug Administration.FDA clears first over-the-counter continuous glucose monitor.Welsh JB, Psavko S, Zhang X, Gao P, Balo AK.Comparisons of fifth-, sixth-, and seventh-generation continuous glucose monitoring systems.J Diabetes Sci Technol. 2024;18(1):143-147. doi:10.1177/19322968221099879Welsh JB, Psavko S, Zhang X, Gao P, Balo AK.Comparisons of fifth-, sixth-, and seventh-generation continuous glucose monitoring systems.J Diabetes Sci Technol. 2024;18(1):143-147. doi:10.1177/19322968221099879ElSayed NA, Aleppo G, Aroda VR, et al.7. Diabetes technology:Standards of Care in Diabetes-2023. Diabetes Care. 2023;46(Suppl 1):S111-S127. doi:10.2337/dc23-S007Blum A.Freestyle Libre glucose monitoring system.Clin Diabetes. 2018;36(2):203-4. doi:10.2337/cd17-0130Shi L, Hellmund R.Cost comparison of flash continuous glucose monitoring with self-monitoring of blood glucose in adults with type 1 or type 2 diabetes using intensive insulin—from a US private payer perspective.US Endocrinol. 2020;16(1):24–30 doi10.17925/USE.2020.16.1.24Association of Diabetes Care & Education Specialists.Weighing CGM pros and cons.Robertson, S.Continuous glucose monitoring in type 2 diabetes is not ready for widespread adoption.Am Fam Physician.2020;101(11):646.Centers for Medicare & Medicaid Services.Therapeutic continuous glucose monitors.Association of Diabetes Care & Education Specialists.CGM (& insulin delivery device) affordability programs.Peters AL, Ahmann AJ, Battelino T, et al.Diabetes technology-continuous subcutaneous insulin infusion therapy and continuous glucose monitoring in adults: An endocrine society clinical practice guideline.J Clin Endocrinol Metab. 2016;101(11):3922-3937. doi:10.1210/jc.2016-2534Beck RW, Riddlesworth TD, Ruedy K, et al.Continuous glucose monitoring versus usual care in patients with type 2 diabetes receiving multiple daily insulin injections: A randomized trial.Ann Intern Med. 2017;167(6):365-374. doi:10.7326/M16-2855Hegedus E, Salvy SJ, Wee CP, et al.Use of continuous glucose monitoring in obesity research: A scoping review.Obes Res Clin Pract. 2021;15(5):431-438. doi:10.1016/j.orcp.2021.08.006Phan V, Kretschmer P, Pittas AG.SAT142 utilization of continuous glucose monitoring in diagnosis and management of insulinoma.Journal of the Endocrine Society. 2023;7(Supplement_1):bvad114.1007. doi:10.1210/jendso/bvad114.1007U.S. Food & Drug Administration.Do not use smartwatches or smart rings to measure blood glucose levels: FDA safety communication.
17 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute of Diabetes and Digestive and Kidney Diseases.Managing diabetes: continuous glucose monitoring.American Association of Clinical Endocrinology.CGM device comparison.Food and Drug Administration.FDA clears first over-the-counter continuous glucose monitor.Welsh JB, Psavko S, Zhang X, Gao P, Balo AK.Comparisons of fifth-, sixth-, and seventh-generation continuous glucose monitoring systems.J Diabetes Sci Technol. 2024;18(1):143-147. doi:10.1177/19322968221099879Welsh JB, Psavko S, Zhang X, Gao P, Balo AK.Comparisons of fifth-, sixth-, and seventh-generation continuous glucose monitoring systems.J Diabetes Sci Technol. 2024;18(1):143-147. doi:10.1177/19322968221099879ElSayed NA, Aleppo G, Aroda VR, et al.7. Diabetes technology:Standards of Care in Diabetes-2023. Diabetes Care. 2023;46(Suppl 1):S111-S127. doi:10.2337/dc23-S007Blum A.Freestyle Libre glucose monitoring system.Clin Diabetes. 2018;36(2):203-4. doi:10.2337/cd17-0130Shi L, Hellmund R.Cost comparison of flash continuous glucose monitoring with self-monitoring of blood glucose in adults with type 1 or type 2 diabetes using intensive insulin—from a US private payer perspective.US Endocrinol. 2020;16(1):24–30 doi10.17925/USE.2020.16.1.24Association of Diabetes Care & Education Specialists.Weighing CGM pros and cons.Robertson, S.Continuous glucose monitoring in type 2 diabetes is not ready for widespread adoption.Am Fam Physician.2020;101(11):646.Centers for Medicare & Medicaid Services.Therapeutic continuous glucose monitors.Association of Diabetes Care & Education Specialists.CGM (& insulin delivery device) affordability programs.Peters AL, Ahmann AJ, Battelino T, et al.Diabetes technology-continuous subcutaneous insulin infusion therapy and continuous glucose monitoring in adults: An endocrine society clinical practice guideline.J Clin Endocrinol Metab. 2016;101(11):3922-3937. doi:10.1210/jc.2016-2534Beck RW, Riddlesworth TD, Ruedy K, et al.Continuous glucose monitoring versus usual care in patients with type 2 diabetes receiving multiple daily insulin injections: A randomized trial.Ann Intern Med. 2017;167(6):365-374. doi:10.7326/M16-2855Hegedus E, Salvy SJ, Wee CP, et al.Use of continuous glucose monitoring in obesity research: A scoping review.Obes Res Clin Pract. 2021;15(5):431-438. doi:10.1016/j.orcp.2021.08.006Phan V, Kretschmer P, Pittas AG.SAT142 utilization of continuous glucose monitoring in diagnosis and management of insulinoma.Journal of the Endocrine Society. 2023;7(Supplement_1):bvad114.1007. doi:10.1210/jendso/bvad114.1007U.S. Food & Drug Administration.Do not use smartwatches or smart rings to measure blood glucose levels: FDA safety communication.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Institute of Diabetes and Digestive and Kidney Diseases.Managing diabetes: continuous glucose monitoring.American Association of Clinical Endocrinology.CGM device comparison.Food and Drug Administration.FDA clears first over-the-counter continuous glucose monitor.Welsh JB, Psavko S, Zhang X, Gao P, Balo AK.Comparisons of fifth-, sixth-, and seventh-generation continuous glucose monitoring systems.J Diabetes Sci Technol. 2024;18(1):143-147. doi:10.1177/19322968221099879Welsh JB, Psavko S, Zhang X, Gao P, Balo AK.Comparisons of fifth-, sixth-, and seventh-generation continuous glucose monitoring systems.J Diabetes Sci Technol. 2024;18(1):143-147. doi:10.1177/19322968221099879ElSayed NA, Aleppo G, Aroda VR, et al.7. Diabetes technology:Standards of Care in Diabetes-2023. Diabetes Care. 2023;46(Suppl 1):S111-S127. doi:10.2337/dc23-S007Blum A.Freestyle Libre glucose monitoring system.Clin Diabetes. 2018;36(2):203-4. doi:10.2337/cd17-0130Shi L, Hellmund R.Cost comparison of flash continuous glucose monitoring with self-monitoring of blood glucose in adults with type 1 or type 2 diabetes using intensive insulin—from a US private payer perspective.US Endocrinol. 2020;16(1):24–30 doi10.17925/USE.2020.16.1.24Association of Diabetes Care & Education Specialists.Weighing CGM pros and cons.Robertson, S.Continuous glucose monitoring in type 2 diabetes is not ready for widespread adoption.Am Fam Physician.2020;101(11):646.Centers for Medicare & Medicaid Services.Therapeutic continuous glucose monitors.Association of Diabetes Care & Education Specialists.CGM (& insulin delivery device) affordability programs.Peters AL, Ahmann AJ, Battelino T, et al.Diabetes technology-continuous subcutaneous insulin infusion therapy and continuous glucose monitoring in adults: An endocrine society clinical practice guideline.J Clin Endocrinol Metab. 2016;101(11):3922-3937. doi:10.1210/jc.2016-2534Beck RW, Riddlesworth TD, Ruedy K, et al.Continuous glucose monitoring versus usual care in patients with type 2 diabetes receiving multiple daily insulin injections: A randomized trial.Ann Intern Med. 2017;167(6):365-374. doi:10.7326/M16-2855Hegedus E, Salvy SJ, Wee CP, et al.Use of continuous glucose monitoring in obesity research: A scoping review.Obes Res Clin Pract. 2021;15(5):431-438. doi:10.1016/j.orcp.2021.08.006Phan V, Kretschmer P, Pittas AG.SAT142 utilization of continuous glucose monitoring in diagnosis and management of insulinoma.Journal of the Endocrine Society. 2023;7(Supplement_1):bvad114.1007. doi:10.1210/jendso/bvad114.1007U.S. Food & Drug Administration.Do not use smartwatches or smart rings to measure blood glucose levels: FDA safety communication.
National Institute of Diabetes and Digestive and Kidney Diseases.Managing diabetes: continuous glucose monitoring.
American Association of Clinical Endocrinology.CGM device comparison.
Food and Drug Administration.FDA clears first over-the-counter continuous glucose monitor.
Welsh JB, Psavko S, Zhang X, Gao P, Balo AK.Comparisons of fifth-, sixth-, and seventh-generation continuous glucose monitoring systems.J Diabetes Sci Technol. 2024;18(1):143-147. doi:10.1177/19322968221099879
ElSayed NA, Aleppo G, Aroda VR, et al.7. Diabetes technology:Standards of Care in Diabetes-2023. Diabetes Care. 2023;46(Suppl 1):S111-S127. doi:10.2337/dc23-S007
Blum A.Freestyle Libre glucose monitoring system.Clin Diabetes. 2018;36(2):203-4. doi:10.2337/cd17-0130
Shi L, Hellmund R.Cost comparison of flash continuous glucose monitoring with self-monitoring of blood glucose in adults with type 1 or type 2 diabetes using intensive insulin—from a US private payer perspective.US Endocrinol. 2020;16(1):24–30 doi10.17925/USE.2020.16.1.24
Association of Diabetes Care & Education Specialists.Weighing CGM pros and cons.
Robertson, S.Continuous glucose monitoring in type 2 diabetes is not ready for widespread adoption.Am Fam Physician.2020;101(11):646.
Centers for Medicare & Medicaid Services.Therapeutic continuous glucose monitors.
Association of Diabetes Care & Education Specialists.CGM (& insulin delivery device) affordability programs.
Peters AL, Ahmann AJ, Battelino T, et al.Diabetes technology-continuous subcutaneous insulin infusion therapy and continuous glucose monitoring in adults: An endocrine society clinical practice guideline.J Clin Endocrinol Metab. 2016;101(11):3922-3937. doi:10.1210/jc.2016-2534
Beck RW, Riddlesworth TD, Ruedy K, et al.Continuous glucose monitoring versus usual care in patients with type 2 diabetes receiving multiple daily insulin injections: A randomized trial.Ann Intern Med. 2017;167(6):365-374. doi:10.7326/M16-2855
Hegedus E, Salvy SJ, Wee CP, et al.Use of continuous glucose monitoring in obesity research: A scoping review.Obes Res Clin Pract. 2021;15(5):431-438. doi:10.1016/j.orcp.2021.08.006
Phan V, Kretschmer P, Pittas AG.SAT142 utilization of continuous glucose monitoring in diagnosis and management of insulinoma.Journal of the Endocrine Society. 2023;7(Supplement_1):bvad114.1007. doi:10.1210/jendso/bvad114.1007
U.S. Food & Drug Administration.Do not use smartwatches or smart rings to measure blood glucose levels: FDA safety communication.
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