For many years, I’ve had trouble with low blood sugar. However, for the last week, things have changed, and my sugar has been 179-197 mg/dl [9.9-10.9 mmol/L] even though I haven’t changed my eating habits. Can you tell me why?

There are many reasons why your blood sugar may rise. It is important to have a check list so you can run through the causes as you notice the change. My list is as follows:

Change in exercise/activity level. Less activity results in higher sugars.
Change in diet. This may also mean hidden calories you may not be aware are there.
Recent illness. Even in the early stages of an illness, even a cold, your sugars can rise.
If you’re taking insulin, the insulin may become degraded by exposure to heat, cold, light, or age. You may still take the same insulin dose but it does less good. In this case, one of your first steps would be to get new insulins.
New medications may aggravate blood sugars.
New schedules may raise blood sugars.
Emotional stress can raise sugars.
Progression of type 2 diabetes may result in your previous oral treatments to be less affective. Roughly 50% of patients with type 2 diabetes end up on insulin when their oral medications become ineffective over time.

I would review this list for any common answers and discuss them with your physician and/or your diabetes care team.

JTL