Why glucose rises after a low with type 1 diabetes
With type 1 diabetes, glucose may initially recover from a low and then rise noticeably above the expected level. This does not always have the same cause. Sometimes too many fast-acting carbohydrates were eaten to treat the low. Sometimes a normal meal, a late snack or fear of another fall adds to this. When a similar situation repeats, it becomes a useful reason to review the charts.
Why glucose may rise after a low
- Too many fast-acting carbohydrates were eaten to treat the low — glucose may then rise above the expected level after the fall.
- Additional food was eaten — sometimes a person eats a normal snack as well as fast-acting carbohydrates after a low, producing a greater rise.
- Fear of another fall — this can lead to treating the low with more carbohydrates than needed.
- A recurring pattern at that time of day — if glucose rises after a low at roughly the same hours, this is a useful pattern to review.
- The pattern depends on the day's circumstances — activity, food, stress and routine can affect the size of the subsequent rise.
How to avoid hasty conclusions
- Do not draw conclusions from one episode: recurring similar rises after lows are more informative.
- Check how many fast-acting carbohydrates were eaten to treat the low.
- Distinguish a rise after fast-acting carbohydrates from one where additional normal food was eaten.
- Compare the times of day when rises after lows occur most often.
- If you use a pump or AAPS, account for active insulin, automatic corrections and the operating mode at that time.
What is particularly useful to check in the charts
- How long after a low glucose starts to rise again.
- How high it rises after treating the low.
- How many fast-acting carbohydrates were eaten and whether there was additional normal food.
- Whether this rise repeats at similar hours or in similar situations.
- Whether there is a link with active insulin, food, stress or time of day.
What to do next
This review makes it easier to identify the more likely cause: too many fast-acting carbohydrates used to treat the low, additional food, fear of another fall or a recurring pattern at that time of day. Change settings after several similar observations, rather than a single difficult chart.