BloodGlucoseValueUnderstand every reading

Blood Glucose 14 tested - mmol/L or mg/dL?

252mg/dL14.0 mmol/L

Most meters outside the US show mmol/L. A reading of 14 is far more likely to be 14 mmol/L than 14 mg/dL.

If it is 14 mmol/L

= 252 mg/dL. Fasting without diabetes: Diabetes range · With diabetes before a meal: High — check ketones

Full explanation for 252 mg/dL →

If it really is 14 mg/dL

That is 0.8 mmol/L — severely low. Most meters show "LO" below 20 mg/dL. If the person is shaky, sweaty, confused or drowsy, treat it as a severe low: 15–20 g of fast sugar if they can swallow safely; if not, glucagon if available, recovery position and call 911 (US) or your local emergency number.

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 — reading 14 mmol/L (252 mg/dL)

252 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 252 mg/dL marked55100126252 mg/dL

2 hours after eating (or glucose tolerance test)

Diabetes rangeScale with 252 mg/dL marked55140200252 mg/dL

If you have diabetes — reading 14 mmol/L (252 mg/dL)

252 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 252 mg/dL marked5480131181241300252 mg/dL

1–2 hours after a meal

High — check ketonesScale with 252 mg/dL marked54180241300252 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.

252 mg/dL as an average: HbA1c 10.4%

If 252 mg/dL were your average glucose over two to three months, it would match an HbA1c of about 10.4% (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 252 mg/dL that means roughly 214–290 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.