Question on non-fasting blood glucose


Hi I am a nursing student in clinicals. Have a diabetic patient (long-standing diabetes mellitus and patient is over age 60, with many health problems from the diabetes ) whose non-fasting blood glucose was running 66-70, tests done about 3 hours after meals. The patient told me her levels usually run around 200. Her nurse was concerned about it being too low and had me give her a snack. The patient had reported dizziness and weakness which she attributed to the lower glucose reading.

But when I talked to my instructor, she said that 60-100 was normal (I thought that was for fasting blood glucose) and there was no problem with the patient.

Is it possible to have a high reading that is normal for you?

Please help me out here with these levels thanks! Any other information I need to look at about the patient?

Specializes in Family Practice.

You are right...60-100 range is for fasting blood glucose. If the pt normally is at 200, she would probably feel weak if her non-fasting bg was 70. However, there probably should be some investigation into why her bg is that low. Check her MAR to make sure that she is receiving the appropriate insulin dosage, if she is taking insulin. You might also want to recheck her labwork, her potassium level may be altered which could also lead to feeling dizzy, weak.



Has 7 years experience.

Maybe your nursing instructor didn't pick up on the "3 hours after meals" part.

That low reading would suggest (to me, could be I am wrong) that a little tweaking is indicated in the insulin arena.

Very good catch! Thank you so much for posting this one!


Daytonite, BSN, RN

4 Articles; 14,603 Posts

Specializes in med/surg, telemetry, IV therapy, mgmt. Has 40 years experience.

well, i disagree with your instructor. i'm a diabetic and at 65 i start having symptoms of hypoglycemia. dizziness and weakness are symptoms of hypoglycemia. and, anyway, the nurse on duty was in charge of your patient, not your instructor and the nurse on duty did the correct thing.

you can get lots of information about diabetes from the website of the national institute of diabetes and digestive and kidney diseases at this address: at this site ( are lots of downloads of patient information on blood sugars and blood testing. you can also find a lot of information by inputting "diabetes" in the search box on the medline plus ( website.

Specializes in ICU, PICC Nurse, Nursing Supervisor. Has 20 years experience.

what is normal for one person may not be normal for another. that is why the 60-100 range is just a estimate. people react differently to variating glucose levels. any patient of mine with a blood sugar of 60 gets a snack and a re-check in 30 minutes.

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