HomeDiabetesThe Pros and Cons of Continuous Glucose Monitoring (CGM)

The Pros and Cons of Continuous Glucose Monitoring (CGM)

You’ve in all probability seen me sporting a small machine on my higher arm in a number of the photographs on this web site. That’s my steady glucose monitor (CGM), a instrument that’s instrumental in my every day diabetes administration. 

It’s a superb piece of apparatus, and I completely like it (more often than not).

Christel with a Dexcom CGM on her arm

What’s CGM?

A CGM machine makes it attainable for me to see my glucose readings in (nearly) real-time and to trace historic glucose knowledge. 

Most CGMs embody three predominant elements: 

  • A small sensor that’s inserted slightly below the pores and skin (the place it reads glucose ranges in interstitial fluid, or the fluid between physique cells)
  • An hooked up transmitter (that is the half you see on my arm), which sends the readings to a receiving machine 
  • A receiver or smartphone that shows the readings and glucose development knowledge

There are at present a number of CGM programs obtainable for private use in america:

My expertise with CGM

I acquired my first Medtronic CGM in December 2012 and wore it day-after-day for 18 months earlier than taking a break. I then ordered my first Dexcom system in August 2016, and that has been my go-to since.

There are professionals and cons to all CGM programs. Since I’ve solely worn Medtronic and Dexcom units to this point, I’ll offer you my opinions based mostly on these so you possibly can determine if a CGM may aid you handle your diabetes higher.

Some great benefits of CGM


Should you do finger-stick blood sugar checks and know your physique properly, you in all probability assume you might have a reasonably good concept of what your sugars are as much as between measurements. Likelihood is good, although, that you could be be mistaken.

I acquired an enormous shock once I began seeing how a lot my blood sugar really diverse all through the day, to not point out throughout the evening once I normally don’t examine. 

CGM is a crucial instrument for offering any such ongoing info over a 24-hour interval that may present traits and patterns, versus the snapshots at sure occasions throughout the day which are offered by conventional monitoring.

Abruptly, I may see how sure meals and actions affected my glucose ranges over the following a number of hours. That info is golden! 

Plus, with the ability to spot low sugars earlier than they hit (due to the alerts I set for when my sugar ranges begin dropping or get to a sure level) has actually minimize down on how typically I’ve low blood sugar episodes. 

It additionally means I’m consuming fewer glucose tablets and fewer juice to take care of mentioned lows, as a result of I’m catching them earlier when much less intervention is required to get my blood sugar again to focus on vary.


So, what to do with all this new info? In my case, it has not solely helped me restrict episodes of hypoglycemia (low blood sugar), however I’ve additionally managed to scale back my A1c degree (a measure of glucose management over the earlier 2 to three months) to round 6.0 %. 

My blood sugar has all the time been fairly well-regulated however has by no means been this secure earlier than.

What’s extra, some present CGM units can combine with an insulin pump, permitting you to observe each glucose and insulin ranges on the identical time. 

And sure units mix CGM and insulin pump know-how with an algorithm that routinely adjusts insulin dosing to assist glucose keep inside goal vary (the optimum degree as decided by an individual’s healthcare supplier), in an innovation often known as hybrid-closed loop (HCL) know-how. 

Present HCL units in the marketplace embody:

After all, simply slapping on a CGM received’t handle your diabetes. However cautious interpretation and use of the information can assist immensely.

As an example, I’ve realized that if I sleep any later than 8 a.m. earlier than taking my morning insulin, I’ll be battling excessive morning blood sugar ranges till a minimum of midday.

I’ve additionally realized what sort of actions will make my sugars drop quick (in my case, that may be strolling), my true ranges of insulin sensitivity all through the day, and that I all the time want a minimal of a half unit of energetic insulin on board (IOB) earlier than a exercise.

Gaining this data took time and did embody a number of missteps, however that’s life and that’s studying. The data has made it attainable for me to optimize my coaching and has made it simpler for me to remain in my desired vary of 90 to 144 mg/dL (5.0 to eight.0 mmol/L) when exercising.

Confidence and safety

My CGM has enabled me to grasp my diabetes higher. It has given me extra confidence in the way in which I handle my situation and has helped me obtain tangible outcomes.

It’s additionally comforting to understand how my sugar ranges are trending. I’ll even enterprise out typically with out bringing all my diabetes gear. I additionally stopped monitoring 10 to 12 occasions a day as a result of I now not have to — the knowledge is all the time proper there on the display in entrance of me.

Utilizing this machine has enabled me to go for a stroll or a hardcore health club session with out fearing lows and to achieve each my health and diabetes well being targets extra effectively.

Christel doing biceps curls in the gym with a Dexcom CGM on her upper armChristel doing biceps curls in the gym with a Dexcom CGM on her upper arm

The disadvantages of CGM


Anyone who has ever worn a CGM is aware of the frustration of doing a conventional finger-stick examine and seeing that the sensor studying is off. 

The explanation behind that is that the know-how isn’t excellent but (though it’s always enhancing) and the sensor measures your glucose ranges within the interstitial fluid and never the blood. (There’s usually a lag of some minutes between your interstitial glucose ranges and blood glucose ranges)

Other than the plain points, it can be outright harmful in case you rely solely on the sensor readings and fully ignore what your physique is telling you. For instance, if the CGM alarms are going off telling you that you’re at 250 mg/dL (13.9 mmol/L), it may be exhausting to not instantly react.

I’ve additionally needed to cease exercises as a result of the sensor incorrectly advised me that my blood glucose was low or about to get low — all the time an annoying situation whenever you’re within the midst of a great health club session.

Though some CGM units are actually extremely correct and authorised by the U.S. Meals and Drug Administration (FDA) for making therapy selections, it’s all the time smart to substantiate any surprising readings or readings that don’t match what your physique is feeling with a conventional finger-stick earlier than taking motion.

(And a number of other of the units in the marketplace, together with the Medtronic Guardian and the Ascensia Eversense E3, require roughly two finger-stick checks a day for calibration.)

That mentioned, it’s value noting that the know-how has improved tremendously through the years. In accordance with a 2023 research, CGMs have been proven to be 96.5 % correct in a real-world hospital setting.


That is really the principle motive why I initially stopped sporting my CGM and why I nonetheless take breaks every so often.

This may occasionally not apply to everybody, however I generally tend to depend on the readings and suggestions a bit too closely. For instance, if the studying mentioned that my glucose was dropping shortly, I might belief it absolutely over how I really really feel. I feel that’s an enormous no-no in relation to diabetes administration. On this situation, it might be prudent to substantiate the CGM info with a finger-stick examine.

I’ve gotten loads higher at utilizing the CGM as a knowledge level and never essentially as the whole reality, which has made it a much better accomplice in administration.


Having the CGM sensor hooked up to my physique on a regular basis may be extraordinarily annoying. It’s not very massive and other people don’t actually discover it, however it will possibly depart considerably unattractive suntan marks, and I additionally are inclined to scar simply.

If I put on it on my abdomen, it tends to get in the way in which when understanding, so I normally put on it on my higher arm. I discover that I get fairly good readings with that placement. (One concern, although, is that it may be a bit of exhausting to get a sweaty sports activities bra off with out ripping on the sensor.)

Sporting it on my higher arm has led to some fairly cool interactions and conversations with curious individuals. I don’t thoughts — I see it as a possibility to teach and advocate. 

But when it bothers you, there are many different areas to position the sensor the place it’s not seen. Typical producers’ suggestions for sensor placement embody the higher arm, abdomen, decrease again, thigh, and buttocks, relying on the precise machine you’re utilizing.

There are adhesives that may assist strengthen the CGM’s adherence to your physique. Consult with the directions that include your CGM and communicate together with your diabetes care supplier about approaches that may give you the results you want.

On a associated matter, many individuals surprise if CGMs damage. In my expertise, there may be solely a slight pinching sensation upon inserting the sensor, and this momentary discomfort is properly well worth the knowledge the machine supplies. 

Plus, for the units at present in the marketplace, the sensors solely should be modified each 7 to 10 days (except for the implantable Eversense E3, which generally must be modified by a healthcare supplier each 90 days).

Associated: Here’s a put up outlining my finest CGM ideas during which I discuss extra about methods to placed on the sensor (with a video) and methods to make it keep on.


Relying in your medical health insurance protection, CGM units and their related provides may be costly. Test together with your insurance coverage supplier to find out what prices are related to CGM for you.

Christel outdoors with weights checking her CGMChristel outdoors with weights checking her CGM

Remaining ideas

Would I like to recommend a CGM to anybody with diabetes utilizing insulin? The reply is a convincing sure, a minimum of till you perceive your physique and your diabetes higher. 

The CGM offers you data about your diabetes that you’ve by no means had earlier than, and if after a whilst you really feel such as you now not want it, communicate together with your diabetes care supplier about different choices.

The important thing for me when utilizing my CGM is to get higher at listening to each the CGM and my physique. It’s a unbelievable machine, however it’s not an alternative to my very own considering and expertise. 

It’s an awesome instrument to have in my diabetes toolbox, however it will possibly’t stand alone.



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