BloodGlucoseValueUnderstand every reading

Blood glucose 249 mg/dL — what does it mean?

249mg/dL13.8 mmol/L
  • Without diabetes, fastingDiabetes range
  • Without diabetes, 2 h after eatingDiabetes range
  • With diabetes, before a mealHigh — check ketones
  • With diabetes, after a mealHigh — check ketones
  • In mmol/L13.8 mmol/L

Check for ketones

  • With type 1 diabetes or on insulin: test for ketones (urine strip or blood ketone meter).
  • Drink water, follow your sick-day plan and take correction insulin as prescribed.
  • Do not exercise if ketones are moderate or high — it can push glucose higher.
  • Without known diabetes: see a doctor today.

If you don't have diabetes

249 mg/dL is in the diabetes range whether fasting or after a meal. A random reading of 200 mg/dL or more together with typical symptoms (thirst, frequent urination, weight loss) is enough for a diagnosis — see a doctor soon.

Fasting (8+ hours without food)

Diabetes rangeScale with 249 mg/dL marked55100126249 mg/dL

2 hours after eating (or glucose tolerance test)

Diabetes rangeScale with 249 mg/dL marked55140200249 mg/dL

If you have diabetes

249 mg/dL is high. Above 240 mg/dL, people with type 1 diabetes or on insulin should check for ketones.

Before a meal / fasting

High — check ketonesScale with 249 mg/dL marked5480131181241300249 mg/dL

1–2 hours after a meal

High — check ketonesScale with 249 mg/dL marked54180241300249 mg/dL

Targets for most non-pregnant adults (American Diabetes Association (ADA) Standards of Care). Your own targets may be different — for example in pregnancy, for children, older adults or people prone to lows. See pregnancy targets.

249 mg/dL as an average: HbA1c 10.3%

If 249 mg/dL were your average glucose over two to three months, it would match an HbA1c of about 10.3% (above the common treatment goal of below 7%). A single reading says little about your HbA1c — it is the long-term average that counts. Learn more in how to measure blood sugar.

Make sure the number is right

  • Wash and dry your hands before a finger-stick: fruit juice or sugar on the skin can raise the result a lot.
  • Home meters may differ from a lab value by up to about 15%. At 249 mg/dL that means roughly 212–286 mg/dL.
  • CGM sensors measure tissue fluid and lag 5–15 minutes behind blood when glucose changes quickly — confirm lows with a finger-stick.

Check another reading

Nearby values

This page explains one reading in general terms. It is not a diagnosis or a treatment instruction. Follow the plan agreed with your doctor or diabetes team.