A SMALL round sensor worn on the upper arm that sends glucose readings to a phone every few minutes, without the need for finger-pricks.
Continuous glucose monitors (CGMs) have evolved from niche gadgets into devices that patients ask me about almost every week.
CGMs are undoubtedly a clever piece of technology, but they come at a cost. So, an important question deserves an honest answer: Is a CGM worth it, and who really benefits from using one?
What does a CGM do?
A traditional finger-prick gives you a single glucose reading at one moment in time. A CGM, on the other hand, provides a continuous stream of readings, creating a running graph of your glucose levels throughout the day and night.
Worn as a small sensor just beneath the skin, a CGM shows not only your glucose level but also which direction it is heading and how quickly it is changing.
In real time, you can see how a plate of rice, a sugary drink, a walk or even a stressful meeting affects your blood glucose levels.
That is the real value of a CGM: it makes invisible glucose patterns visible. Many people are surprised to discover how something they perceive as “healthy,” such as fruit juice, can cause their blood sugar levels to spike, while a simple evening walk can help bring them down gradually.
For some people, a CGM is more than just a convenience; it can be a vital safety tool. For those on insulin, particularly people prone to dangerous episodes of low blood sugar, continuous readings and alerts can provide an important safety net, warning them of falling glucose levels before the situation becomes an emergency.
For people struggling to understand why their blood sugar levels are erratic, a couple of weeks of continuous data can reveal patterns and triggers that occasional finger-prick tests may miss. Used appropriately, a CGM can be a powerful tool for both learning and improving safety.
My honest take
For someone with well-controlled type 2 diabetes, who manages their condition with tablets, has an HbA1c within the target range and is not prone to low blood sugar, a CGM is a nice-to-have gadget rather than a necessity.
A short trial can offer valuable insights into how food, physical activity and daily habits affect glucose levels. However, wearing one indefinitely may add to the cost without necessarily leading to meaningful improvements in diabetes management.
There is also a risk of anxiety, with some people becoming overly fixated on every small fluctuation in the graph, even though blood glucose naturally rises and falls throughout the day.
A CGM is worth the investment when it helps you make meaningful changes to your habits, improve your glucose control or recognise falling blood sugar levels early enough to prevent a potentially dangerous episode.
Ultimately, its value lies not in the data it provides but in how that information helps you make better decisions about your health.
It is less worthwhile when it becomes an expensive source of numbers that add little to what you were already managing well.
Sense and sensibility
Technology is a tool, and a CGM is certainly a useful one. But, like any tool, its value depends on whether it helps you do something better.
For some people, the answer is a clear yes. For others, regular finger-prick tests and HbA1c monitoring may be all they need to keep their diabetes well managed.
If a CGM turns you into an anxious observer of every fluctuation in your glucose readings, it may do more harm to your peace of mind than good for your diabetes control.
The goal is to gain useful insights that help you manage your health better, not to live in a state of constant worry over every rise and fall.
If you are curious about using a CGM, a sensible middle ground is to wear one for a couple of weeks as a focused learning exercise, ideally with guidance from your doctor. Pay attention to what the readings reveal about your body and daily habits.
Look at which foods cause your blood sugar to spike, how physical activity such as walking affects your glucose levels, and what happens overnight.
Then decide whether continued use offers enough benefit to justify the cost or whether you have learnt what you need to know and can return to finger-prick testing and HbA1c monitoring with a better understanding of your glucose patterns.
A CGM is a valuable tool, particularly for people on insulin or those prone to dangerous episodes of low blood sugar, for whom it can be life-saving.
For others with well-controlled diabetes, it may serve best as a short-term learning tool rather than a lifelong necessity.
Dr Eason Chang is a physician and diabetes and metabolic health educator. He is the founder of DREC Healthcare Academy Sdn Bhd, which promotes diabetes prevention, management and reversal through sustainable lifestyle and nutrition interventions. The information provided is for reference only. Comments: letters@thesundaily.com