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What Happened? Dealing With Unexpected Highs and Lows


You’re on top of your diabetes and then your blood glucose test results show that your levels have unexpectedly gone off track. What happened? Use this assessment tool to help find answers.


You think you’ve got a good handle on your diabetes. You’ve figured out what your body needs and are on top of your blood glucose. And then – out of nowhere – your blood glucose levels go off track. This can be especially true when the seasons change and your activity or eating habits may change, too.

It can be frustrating to have an unexpected high or low when you do your best at managing your diabetes. But, it happens. Diabetes requires so much oversight every day. And once in a while, things can go a little awry.

Try to focus on moving forward by taking a step back. Look closely at the time during which you saw these unexpected results. This Assessment Tool can help :

Ask yourself:

  1. Did my diet change, even slightly?

    Tip: This includes eating later than planned, skipping a meal, or eating more or less than usual.

  2. Did I drink alcohol?

    Tip: Think about both the type and amount of alcohol. Different alcoholic drinks affect blood glucose levels differently.

  3. Have I been under more stress than usual?

    Tip: Ask someone close to you if they’ve noticed anything, as it’s not always easy to see this in yourself.

  4. Was I sick at any point?

    Tip: Even a mild cold can impact your blood glucose levels.

  5. Was I less or more active recently, or exercising in a new way that is at a different intensity than usual?

    Tip: This includes things that don’t seem like exercise, like mowing the lawn or shoveling the snow.

  6. Is my blood glucose meter working ok? Are my test strips still good?

    Tip: Do a test with control solution to check the accuracy of your meter and test strips.

  7. Is there a new pattern in my highs and lows?

    Tip: If you’re still experiencing highs or lows, chart your results for the upcoming week, plus your eating and exercise to look for patterns.

  8. Do I need to test my blood glucose more often?

    Tip: You may want to test more frequently, as recommended by your healthcare team, when you’re experiencing unexpected highs or lows.

  9. Did I change anything in my insulin therapy?

    Tip: This includes your insulin dose, delays in injections or a pump disconnection, or change in injection site area (for example, from stomach area to thighs).

It’s not always possible to pinpoint exactly what caused your blood glucose to rise or fall unexpectedly but tracking your test results gives you valuable insight. Set up an appointment with your healthcare team to discuss your results and to decide on a course of action.




Mayo Clinic Staff. (2020, June 06). Diabetes management: How lifestyle, daily routine affect blood sugar. Retrieved March 12, 2021, from