Is a fasting blood sugar of 109 normal?
No. A fasting blood sugar of 109 mg/dL (6.1 mmol/L) is in the prediabetes range, which runs from 100 to 125. One morning isn't a diagnosis: repeat it at a lab with an A1c, and treat it as an early warning you can turn back.
NormalPrediabetes rangeDiabetes range
What it means
Fasting means 8 hours or more with no calories, water only. Under 100 mg/dL (5.6 mmol/L) is normal, 100 to 125 (5.6 to 6.9) is the prediabetes range, and 126 (7.0) or more is the diabetes range. 109 sits 17 points under the diabetes line, and 10 points from normal.
Can this number decide it?
Only a lab test decides a band, and a diagnosis takes two results unless the number is clearly high. A finger-stick meter or a sensor can't diagnose, and a sensor runs higher than your blood.
What to do
Repeat it at a lab with an A1c. If it holds, the plan that cut new diabetes by 58% in the biggest trial is to lose 5 to 7% of your weight if you carry extra, walk 150 minutes a week with 10 minutes after meals, and retest in 12 weeks. Work out your plan.
When to get help now
Call 911 or go to the ER if a blood sugar stays at 300 or more, or comes with vomiting so you can't keep fluids down, fruity breath or hard breathing. Under 70 with confusion, fainting or trouble swallowing is an emergency too. Pregnancy uses tighter numbers, so take any number to your midwife or doctor, and if you take insulin or a sulfonylurea, your targets come from your prescriber.
