My mom (45F) had a fasting blood sugar test after ~8 hours fasting that came back 216 mg/dL. Two days later, with almost the same diet and again ~8 hours fasting, her fasting sugar was 87 mg/dL. No major medication changes in between. Is this kind of sudden drop normal, or does it need further testi
You can't tell much from single readings which is why CGM's are such a game changer for us. Were those 2 readings taken at the same time of day?
There's nothing abnormal about that for a T2 diabetic.
Blood glucose levels fluctuate and in T2s can be quite unpredictable. The fluctuations depend on a lot of things such as:
Activity
What foods she had (even the evening before)
Stress
How well her body responds to insulin on a given day / how well her insulin production is on a given day
Etc, etc.
Either way, it's not unusual at all to see a fasting glucose of 85 and a fasting glucose of 250 on two separate days in a T2 diabetic.
What's really important is her HbA1C as well as her general time in range (which can be only measured with a CGM)
Something has changed even though you say it hasn't. Not major changes in medication, says to me there were some changes and I doubt someone eats exactly the same thing, days in row (without being a bodybuilder). Maybe she moved more, maybe she didn't ate as late in the day, maybe she missed some cake or is not sick anymore (that if she had the flu or something else) Maybe she drank more water or changed CGM ( if she wears one) or maybe it was the insuline.
I remember facing the same puzzle with my own mom. One day her fasting sugar shocked us and two days later it looked perfectly normal. I felt confused and even a little scared. A single test can jump because of stress poor sleep illness or lab variation. I told her she needed repeat fasting tests and an HbA1c to see the longer pattern. That gave us real clarity and guided the next steps.
I remember facing the same puzzle with my own mom. One day her fasting sugar shocked us and two days later it looked perfectly normal. I felt confused and even a little scared. A single test can jump because of stress poor sleep illness or lab variation. I told her she needed repeat fasting tests and an HbA1c to see the longer pattern. That gave us real clarity and guided the next steps.