How wide are the shaded bands?

The width of the blue and grey bands gives you an idea of how much your glucose varies day to day and due to occasional changes in routine

• A wide BLUE band suggests that blood glucose levels vary a lot on most days
• A wide GREY band suggests that blood glucose levels are varying due to occasional events that have a significant effect on blood glucose

The following example shows wide bands (sometimes known as “billowing” or “ballooning”). Although the HbA1c is good, the blood glucose levels are very variable, particularly in the early morning.

‘Bursting the balloon’ can be challenging; however, there are some good places to start. These include looking at:

Wide blue band

Think about when the bands are widest. Typically, this will relate to insulin doses and mealtimes, so you can use the same approach as you would if the problem was “rollercoaster” blood glucose as above, i.e.

Insulin doses

• Have you missed doses of insulin?
• Are you over-correcting highs?
• If you are carbohydrate counting, is your insulin-to-carbohydrate ratio correct?
• If you are carbohydrate counting, is your correction dose correct?
• Timing
  • Have you given your insulin after a meal?
  • Do you need to give your insulin a bit earlier before you eat?

Carbohydrates

• Are you counting carbohydrates correctly?

Wide grey band

Think about occasional events such as:

• Unplanned meals/snacks
• Intermittent/unplanned exercise
• Alcohol
• The difference between what you do during the week and what you do at weekends

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If you are in any doubt or have any questions about your blood glucose levels, then speak to your diabetes care team.

To continue, click on the ‘CGM Quiz’ below.