BloodGlucoseValueUnderstand every reading

Blood glucose 310 mg/dL — what does it mean?

310mg/dL17.2 mmol/L
  • Without diabetes, fastingDiabetes range
  • Without diabetes, 2 h after eatingDiabetes range
  • With diabetes, before a mealVery high
  • With diabetes, after a mealVery high
  • In mmol/L17.2 mmol/L

Get medical advice now

  • Check ketones if you use insulin. Moderate or high ketones, vomiting, abdominal pain, deep fast breathing or fruity-smelling breath can mean diabetic ketoacidosis — call 911 (US) or your local emergency number or go to the emergency room.
  • Very high readings (especially above 600 mg/dL, often shown as "HI") with extreme thirst, confusion or drowsiness can mean hyperosmolar hyperglycemic state — an emergency.
  • Otherwise contact your care team today and re-check every 2–3 hours.

If you don't have diabetes

310 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, today.

Fasting (8+ hours without food)

Diabetes rangeScale with 310 mg/dL marked55100126310 mg/dL

2 hours after eating (or glucose tolerance test)

Diabetes rangeScale with 310 mg/dL marked55140200310 mg/dL

If you have diabetes

310 mg/dL is very high. Check ketones if you use insulin, and contact your care team if it stays above 300 mg/dL or you feel unwell.

Before a meal / fasting

Very highScale with 310 mg/dL marked5480131181241300310 mg/dL

1–2 hours after a meal

Very highScale with 310 mg/dL marked54180241300310 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.

310 mg/dL as an average: HbA1c 12.4%

If 310 mg/dL were your average glucose over two to three months, it would match an HbA1c of about 12.4% (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 310 mg/dL that means roughly 264–357 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.