I have hypothyroidism and hypertension, and during a routine doctor’s visit, I had a random blood sugar of 17 mmol/L [306 mg/dl], and the nurse said 5 mmol/L [90mg/dl] was around normal. I have an appointment to see the doctor next week about my tests, but before I see him, does a blood sugar of 17 mmol/L [306 mg/dl] mean that I have sugar diabetes?

I would suggest that the blood sugar of 17 mmol/L [306 mg/dl] is high. It is very possible you have diabetes. However, the diagnosis of diabetes requires more than one blood test before the diagnosis can be made. Please see your physician to obtain the appropriate confirmatory labs.

JTL

[Editor’s comment: Testing for diabetes should include blood sugar levels performed by a medical laboratory. The timing of the sample (fasting, random, or postprandial) would influence how high a level is considered abnormal. See Classification and Diagnosis of Diabetes for further information.

Another test, the glycosylated hemoglobin, might be used to help confirm a suspected diagnosis of diabetes, but the GHB (also called HbA1c or A1c) is not usually considered as appropriate to make an initial diagnosis. Antibody testing is occasionally done as a screening test in high-risk situations, or as confirmatory of type 1A (autoimmune) diabetes, but is not part of routine testing.

Urine sugar tests or home glucose testing, if done, might be positive, which would make the situation more urgent to get lab testing done to confirm the abnormal results. However, urine or home glucose testing, if negative, would not exclude diabetes.

WWQ]