A guide to choosing and using the right device for Continuous Glucose Monitoring

woman choosing which cgm device is best

The rhythm of daily life can often be disrupted for those who are managing diabetes. With the relentless cycle of blood glucose monitoring, checking levels several times a day, it can feel like a full-time job—one that is both physically taxing and emotionally draining.

Continuous glucose monitoring (CGM) devices have emerged as revolutionary tools for individuals managing diabetes.. 

A continuous glucose monitoring device is a small, wearable device designed to track glucose levels around the clock, offering a near continuous stream of data that goes beyond the capabilities of traditional glucose monitoring. 

Unlike conventional methods that involve periodic finger stick tests, a CGM device provides a near constant stream of information, painting a more dynamic picture of how the body processes glucose. 

They are more than simply convenient. They’re comprehensive. A CGM device can offer a holistic understanding of their glucose levels—instead of a simple snapshot provided through traditional tracking methods—and transform the management of diabetes

Types of CGM devices

Continuous glucose monitoring devices have evolved over the years and are more able to cater to the diverse needs and preferences of the users. There are now two options to choose from, allowing users to choose the option that aligns with their lifestyles and diabetes management goals. 

The two main types of CGM devices are real-time and intermittent. 

Both help to track blood sugar levels and include a sensor that is inserted into the subcutaneous tissue of the arm or abdomen. And both include a receiver of some sort. The difference is in how and when this data is transmitted. 

Real-Time CGM Devices

Real-time continuous glucose monitoring devices do exactly what you’d imagine: they deliver glucose levels in real time. These devices provide users with continuous insights into their glucose levels, empowering them to make informed decisions promptly.

Benefits of real-time CGM devices include: 

  • Can be connected to a smartphone app or even integrated directly with the user’s insulin pump.
  • Immediate feedback on how food, exercise, and other factors impact glucose levels.
  • Early detection of highs and lows, enabling timely interventions.
  • Customizable alarms and alerts for proactive management.

Cons of real-time CGM devices include: 

This type of CGM device is more dynamic and convenient, but it is also more expensive and is not currently covered by Medicare. 

Intermittent CGM Devices

Some don’t consider these continuous glucose monitoring devices as they don’t provide the same continuous stream of data that real-time devices provide. In fact, many refer to intermittent CGM devices as flash glucose monitoring (FGM) devices. 

Unlike real-time monitors, users need to actively initiate a scan using a dedicated reader or a smartphone app to obtain glucose readings.

Benefits of intermittent CGM devices include:

  • Lower cost device that is covered by most insurance companies as well as Medicare
  • Can be connected to a smartphone app

Cons of intermittent CGM devices include:

  • No customizable alerts
  • No continuous information stream, meaning users will still need to schedule their glucose checks
  • Cannot be calibrated to ensure accuracy*

* CGM devices utilize the interstitial fluid to determine blood glucose levels. But, the interstitial fluid levels and the actual blood glucose levels rise at different rates. This means the data may be slightly skewed. While many devices have a built-in algorithm to try and combat this issue, they do still require occasional calibration through finger stick testing for ultimate accuracy. 

How to choose a CGM device

While there are two main types of CGM device, there are many different brands and devices to choose from. There are a range of options that cater to users’ diverse needs. 

To select the right CGM device for your unique requirements, consider the following key factors:

Accuracy and Reliability

Evaluate the accuracy and reliability of the devices before making a final decision. You’ll want to look for devices with proven accuracy and determine whether the device requires frequent calibrations—and whether or not that suits your needs. 

Sensor Size and Placement

Remember that this sensor will be worn for a period of time, so comfort is a factor in your decision-making. Consider the size of the sensor and the placement options. Devices that are smaller may be more comfortable and those with more flexible placement options can provide options should one area be more suitable to your lifestyle. 

Wear Time and Longevity

Typically, a CGM sensor is designed to be worn for 7-14 days. Though, there are some implantable devices that are meant to last longer, some up to six months. So, you will want to at least consider the sensor’s lifespan when making your decision. 

How often do you need to replace it? And, how well does the adhesive patch hold up during that time frame?

Data Display and Connectivity

Evaluate the user interface. Is it user-friendly and easy to navigate? Does it align with your preferences? 

You may also want to consider the integration options. Is there a smartphone app that you can connect to? And, if so, you may want to know if wifi is required or if offline monitoring is at all possible? Does it integrate with your insulin pump for more accurate delivery of your doses?

Cost and Insurance Coverage 

The cost of a continuous glucose monitoring system is certainly a key factor when making your decision. CGM devices can be expensive if paying out of pocket. Monthly costs can range from $300 and upwards depending on the device chosen. 

You will want to compare costs of the potential devices, including the sensor and required accessories. You will also want to check if your insurance covers the device and its associated costs. 

Intermittent devices are cheaper and covered by Medicare, but they may not be the best choice for you. So, don’t make your decision based on cost alone. 

Features and Customization

Explore the range of customizable alerts and alarms for high and low glucose levels. What are the trend analysis features? What kind of insights does it provide? How often does it need to be calibrated?

These are all questions you should be asking when making your decision. 

How to use a CGM device

Inserting the sensor

Unless you’ve opted for an implantable device, you will need to regularly insert the sensor of your CGM device. Sensors last 7-14 days on average, so this will be something you do with regularity. 

Each brand and model will have its own instructions for how to properly insert the sensor, but there are some general rules and procedures to follow. 

  1. Gather your supplies. Naturally, your first step should be to ensure you have all the necessary supplies, including the CGM sensor, applicator, alcohol wipes, and any additional items specified by the manufacturer.
  2. Wash your hands. And the area where you plan to insert the sensor. Proper hygiene is extremely important if you want to avoid infection. The most common locations for insertion are the abdomen or back of the upper arm. Make sure to avoid areas with scarring, tattoos, or existing irritation. 
  3. Prepare the sensor. Remove the sensor applicator from its packaging. Check for any visible damage to the sensor or its components. If there are instructions from the manufacturer for prepping the sensor, then you should follow those as well.
  4. Insert the sensor. Follow the manufacturer’s instructions for sensor insertion. Typically, this involves removing a protective cover, attaching the applicator to the sensor, and applying gentle pressure to insert the sensor under the skin. This will be breaking some layers of skin, so you may feel a slight pinch or pressure during insertion. 
  5. Secure the sensor. Once insertion is complete, you’ll want to secure the sensor to prevent it from being accidentally removed. Some devices may have adhesive patches to keep the sensor attached to the skin.
  6. Activate the sensor. Use your smartphone app or dedicated reader to activate the sensor. Follow the on-screen prompts to initiate the monitoring process.

Calibrating the sensor

Some CGM devices require manual calibration with blood glucose readings for accurate performance. Check the manufacturer’s instructions to determine if your device needs calibration. If it does, you should follow the manufacturer’s instructions to ensure this process is completed with 100% accuracy. 

Generally, to calibrate the sensor, you will need to compare the sensor’s readings to a traditional blood glucose meter reading. 

You will need to perform a traditional blood glucose test, typically through a finger stick test. Then you’ll need to enter that information into your app and complete the calibration. 

Wearing and caring for the sensor

Though your sensor will typically last for 7-14 days, properly caring for it can help to maximize its lifespan. Here are some tips for wearing and caring for your sensor:

  • Avoid using creams, lotions, or oils on the skin where the sensor is placed, as they may interfere with adhesion.
  • Ensure the sensor is securely attached to the skin. If you notice any peeling or detachment, use medical tape or additional adhesive products recommended by the manufacturer.
  • Follow the manufacturer’s guidelines regarding water resistance. Some sensors are waterproof, while others may have limitations.
  • Wear loose-fitting clothing to avoid unnecessary friction or pressure on the sensor.
  • Take precautions during intense physical activities to protect the sensor.
  • Use additional adhesive or protective coverings if needed.
  • Store unused sensors according to the manufacturer’s recommendations, typically in a cool, dry place.

Viewing and interpreting your CGM data

You can’t benefit from the continuous stream of data your CGM device provides if you’re not viewing the results and watching the trends. The CGM sensor will transmit the information to the reader every few minutes. 

To view the data, you will need to use the provided reader or the app your device integrates with. 

The main screen typically displays your current glucose level. This is the most recent reading from the CGM sensor. But, you should also be able to access trend graphs or charts that show how your glucose levels have been changing over time.

You can also set alerts, warnings, and alarms in the app to help you take timely action when necessary.

Interpreting your data can be slightly more complicated. Your app may identify certain trends for you, but you can also look for these yourself in the charts provided. To interpret data:

  • Look for patterns in your data, such as post-meal spikes or overnight lows. 
  • Pay attention to the percentage of time your glucose levels spend in the target range. 
  • Correlate your glucose data with daily activities, such as meals, exercise, and stress. This can help you understand how different factors influence your glucose levels.

Tips for living with a CGM device

Living with a continuous glucose monitoring device can take a lot of the stress out of your diabetes management, making it more…manageable. But, that doesn’t mean you can simply insert and ignore. 

Here are some tips to help you navigate life with a CGM device effectively.

Set Realistic Goals

Work closely with your healthcare team to establish realistic goals for glucose control, time in range, and other relevant metrics. Don’t expect things to happen all at once. Make gradual adjustments to your lifestyle and treatment plan based on CGM data. Set achievable goals and celebrate small victories.

Thankfully you have plenty of data to work with. Leverage CGM data to identify patterns and areas for improvement. Set goals that align with these insights, such as minimizing post-meal spikes or increasing time in range.

Manage Alerts and Alarms

Tailor alerts and alarms to your preferences and needs. Set thresholds that align with your target glucose ranges, and adjust as necessary. Don’t let your monitoring app become the “boy who cried wolf.” Customize the urgency and frequency of alerts to avoid unnecessary interruptions while ensuring critical notifications are not missed.

Share CGM Data

If desired, share your CGM data with trusted individuals, such as family members or caregivers, using the sharing features available on the CGM device or app. This will help your care team to better support you and your needs. 

Take control of your diabetes

Living with a CGM device is a dynamic process that involves continuous learning and adaptation. But, it can provide unbeatable insight into your glucose fluctuations and how to live a healthier life—even preventing some of the long-term complications that come with improper diabetes management. 

Take control of your health and your diabetes with a continuous glucose monitoring device. No need to Google ‘how to get a continuous glucose monitor’. Heally makes it easy. Get a CGM prescription online now!


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