A continuous glucose monitor is a wearable device that automatically estimates your blood sugar levels throughout the day and night, providing data in real time.
“A CGM is used by people living with diabetes in order to estimate glucose, or blood sugar, levels every few minutes and keep track of it over time,” says Toby Amidor, a New York City-based registered dietitian, author of Up Your Veggies: Flexitarian Recipes for the Whole Family and Diabetes Create Your Plate Meal Prep Cookbook and a Forbes Health Advisory Board member. CGMs help the person with diabetes know what their blood glucose level is at any time and allows them to see any changes or trends throughout the day. “This also helps the health care provider and the individual make more informed decisions about diet, medications and exercise,” she adds.
CGMs have a sensor that is placed under the skin, which transmits readings to a wearable device or smartphone, says Vandana Sheth, a registered dietitian nutritionist and diabetes care and education specialist based in California.
How Do Continuous Glucose Monitors Work?
CGMs have three parts, according to Amidor:
- Sensor: The sensor is inserted under the skin, in the arm or belly, and kept in place with a sticky patch. There is also the option of implanting a sensor in the body. “The sensor estimates glucose levels in the fluid between the cells, which is similar to blood glucose levels,” explains Amidor. “Either type of sensor needs to be replaced; the timing depends on the type of sensor you have.”
- Transmitter: The transmitter sends the information regarding glucose levels without using a wire.
- Software program: “This stores the information received by the transmitter on a smartphone, insulin pump or onto a separate receiver,” says Amidor.
These three parts work together to detect and display the individual’s levels of glucose. “With the continuous glucose monitor, you can see fluctuations in blood sugar levels throughout the day,” explains Theresa Shank, a registered dietitian based in Philadelphia. This, she explains, can provide physicians with crucial information about the patient, such as if their medication therapy needs to be adjusted. Many CGMs have the ability to send readings and reports straight to the physician, she adds.