One way to think of this is that regular blood sugar checks are like snapshots, while RT-CGM is more like a video. RT-CGM can give an almost continuous picture of what is happening with the blood sugar, so it may:
- Reduce the need for doing so many finger-sticks but will never replace essential finger-sticks.
- Help to show if blood sugar is rising or falling with trend arrows.
- Allow people to reduce high and low blood sugars by changing insulin doses, eating or exercise regimens if needed.
- Teach you how insulin, eating and exercise affect your blood sugar level.
- Reduce your worry, since alarms can warn about blood sugar changes.
Using an RT-CGM adds some work to daily diabetes care. Sensors have to be replaced every few days (usually 3-7 depending on the company). Blood sugar checks are needed to adjust or "calibrate" the RT-CGM. The RT-CGM results and alarms may cause more hassles in daily life, especially at work or school. If you use the RT-CGM daily, it may add an hour or more to your daily diabetes routine. But, that extra time may be repaid by doing fewer finger-sticks, having fewer high or low blood sugars, and overall keeping diabetes in better control. Like any other tool, the more effort and care you put into it, the more you will get out of using RT-CGM.
No. All of the RT-CGM devices that have FDA approval right now add to, but don't replace, regular blood sugar checks with a meter. For all of them, you must do some finger-stick blood sugar checks to set or "calibrate" the RT-CGM readings. And there will be times when the RT-CGM readings don't quite make sense. Before making any management decisions, a finger stick check must always be done on a meter.
Adding RT-CGM to diabetes care also could cause some problems. The most common problems you should expect are:
- The RT-CGM may show that the glucose is too high or too low when it's really OK.
- The RT-CGM may show that the glucose is OK, when it is really too high or too low.
- Since RT-CGM measures glucose in the fluid between cells and not in blood, RT-CGM results may lag behind glucose meter results by 15-20 minutes. So, sometimes RT-CGM readings won't match meter readings done at the same time.
- Putting in the sensor is an additional "site" on the body.
- Sleep may be interrupted by alarms.
- Skin problems and rashes where the sensor is placed may occur although there a certain tips for taping that can help. See tips on side of this page.