“What Is Going on With My Blood Sugar?”

Do you ever notice that your blood sugar is higher or lower than usual, and you don’t know why? Here’s a short list of potential explanations compiled by the BETTER team.

Lower than usual blood sugar

  • Meal bolus administered twice. If you use an insulin pump, you can view your history of administered boluses. If you’re on multiple daily injections, you can get an insulin pen that “memorizes” administered boluses.
  • Different injection sites have different absorption rates. For instance, insulin that is injected in the abdomen, in the arm or in a muscle (if you don’t use the right type and length of catheter or needle) will be absorbed more quickly.
  • After you’ve done physical activity, you could experience lower blood sugars for up to 48 hours. Be extra mindful of monitoring your blood sugar throughout the night.
  • Alcohol consumption increases the risk of hypoglycemia for about 24 hours. BE CAREFUL! Glucagon (a hormone that doubles as an emergency treatment for severe hypoglycemia) is less effective when blood alcohol concentration is high. This hormone sends a signal for the liver to release stored glucose. But since the liver is busy metabolizing alcohol, it will be less responsive to glucagon.
  • Stopping the use of drugs that raise blood sugars, such as cortisone (prednisone).
  • Addison’s disease (adrenal insufficiency). This rare condition is characterized by an insufficient production of cortisone by the body. If you have any concerns, please talk to your doctor.

Higher than usual blood sugar

  • Missed insulin bolus. If you use an insulin pump, you can view your history of administered boluses. If you’re on multiple daily injections, you can get an insulin pen that “memorizes” administered boluses.
  • Starting to use a drug that raises blood sugars, such as cortisone (prednisone). 
  • Improper insulin storage, i.e., at a temperature that is either too hot or too cold, can destroy insulin molecules and increase the risk of hyperglycemia. Make sure to check your insulin’s expiration date. To better understand how to properly store insulin, see this BETTER article.
  • An infection or illness will cause an inflammatory response that can raise blood sugar levels. Unexplained hyperglycemia can be a good indicator of a symptomless infection.
  • Dawn phenomenon is the blood sugar increase that people with type 1 diabetes experience in the morning’s early hours. This increase is caused by various hormones, like cortisol, that boost the release of sugar by the liver.
  • Acatheter issue (bent, pulled out, etc.) if you use an insulin pump.

It is recommended to check your ketone bodies when your blood sugar is high (generally over 15.0 mmol/L).à

Other factors that can make your blood sugar high or low

  • Miscalculating carbs or an insulin dose 
  • Eating foods that are high in fat or protein 
  • High physical or psychological stress
  • Hormonal changes (period, menopause) 
  • Weather conditions, especially heatwaves  
  • Change in schedule that affects sleeping hours and mealtimes (new work schedule, trip, etc.)
  • Change in fitness habits 
  • Lipodystrophies

Type 1 diabetes is an unpredictable illness. Blood sugar levels can be hard to manage even on a typical day and will often be higher or lower than usual for no obvious reason. Although frustrating, this is common and normal. Checking your blood sugar more often or using a continuous glucose monitoring system will help you to spot and manage these situations.

If you’re worried about your blood sugar levels, don’t hesitate to reach out to your healthcare team.

Visit the SUPPORT online platform to see all our type 1 diabetes tips. 

You must complete the first two questionnaires of the BETTER registry to access this platform.

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