Have you ever experienced symptoms of hypoglycemia only to find blood sugar is not actually low? Are you feeling anxious about your healthcare team's recommendation to increase insulin because you are feeling worse now that blood sugar is closer to target? You may be experiencing pseudo-hypoglycemia (or false hypoglycemia, false lows).
What is pseudo-hypoglycemia?
Pseudo-hypoglycemia (sometimes referred to as relative hypoglycemia, false hypoglycemia, false low) is when you experience symptoms of hypoglycemia (e.g. shaky, sweaty, dizzy, unwell) despite having blood glucose (sugar) levels that are not clinically low. Your blood sugar when tested is 4.0 mmol/L or higher.
What causes pseudo-hypoglycemia?
The most common cause of pseudo-hypoglycemia is rapid improvement of blood sugar control in people used to high blood sugar levels. As a result, you may experience hypoglycemic symptoms at blood sugar levels above 4.0 mmol/L.
For example, your blood sugar trended around 15 mmol/L over a long period of time. Your doctor recently started you on insulin. Now that blood sugar is improving, you find yourself experiencing symptoms when blood sugar is in the 5 - 6 mmol/L range.
Chronically high blood sugar levels can alter your body’s set point or threshold for activating hypoglycemic symptoms.
I like to use the analogy of temperature. If you are used to living in the tropics and recently moved to Canada, you may find 10 degrees celsius to be freezing! But for those used to living in Canada, 10 degrees can feel quite comfortable!
Just as you would adapt to the colder Canadian temperatures over time, the perception of hypoglycemic symptoms at higher blood sugar levels will resolve over time as your body gets used to this new normal.
How to relieve symptoms of pseudo-hypoglycemia?
If you are experiencing symptoms of low blood sugar, it is always recommended to test blood sugar to check if you having true hypoglycemia (low blood sugar, blood glucose = < 4 mmol/L). If you are using a Freestyle Libre, confirm with a finger-prick blood sugar test.
Once you have ruled out true hypoglycemia (blood sugar below 4 mmol/L), you can treat the symptoms of low blood sugar with a small amount of carbohydrates. Although blood sugar is not low, it is okay to treat with carbohydrates to relieve symptoms.
The typical treatment for true hypoglycemia is 15g of fast-acting sugar. 15g of fast-acting sugar should raise blood sugar by about 2.1 mmol/L in 20 minutes. With pseudo-hypoglycemia, you may find that you need less than 15g to provide symptom relief (e.g. 5 - 10g) while avoiding driving blood sugar too high.
How to meet blood sugar targets with pseudo-hypoglycemia?
If you are experiencing episodes of pseudo-hypoglycemia, be sure to discuss it with your healthcare team!
The goal remains to improve blood sugar to target range to reduce the risk of diabetes complications. However, your healthcare team may recommend a slower progression towards target blood sugar. This would give your body more time to adjust to lower blood sugar ranges and make the process of improving blood sugar better tolerated!
Canadian Diabetes Association. Building Competency in Diabetes Education: The Essentials (5th Ed.). Toronto: Canadian Diabetes Association. 2019.
McDermott, MT. Management of Patients with Pseudo-Endocrine Disorders. Cham: Springer Nature Switzerland AG. 2019.
Seaquist ER, Anderson J, Childs B, et al. Hypoglycemia and diabetes: a report of a workgroup of the American Diabetes Association and the Endocrine Society. Diabetes Care. 2013;36(5):1384-1395.
Yale J, Paty B, Senior PA. Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada: Hypoglycemia. Can J Diabetes. 2018;42(Suppl 1):S104-S108.