Blood Glucose 66 mg/dL tested - is it bad?

If you don't have diabetes

66 mg/dL is below the normal range. Mild dips can follow intense exercise, a long gap between meals or a high-carb meal (reactive hypoglycemia). Eat something, re-check, and mention repeated lows to your doctor.

If you have diabetes

66 mg/dL is level 1 hypoglycemia (54–69 mg/dL). Treat it now with 15–20 g of fast-acting carbohydrate and re-check after 15 minutes (see the box above).

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.

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 66 mg/dL that means roughly 56–76 mg/dL.
• CGM sensors measure tissue fluid and lag 5–15 minutes behind blood when glucose changes quickly — confirm lows with a finger-stick.

Nearby values

• 61 mg/dL
• 62 mg/dL
• 63 mg/dL
• 64 mg/dL
• 65 mg/dL
• 67 mg/dL
• 68 mg/dL
• 69 mg/dL
• 70 mg/dL
• 71 mg/dL

Sources: ADA Standards of Care · ADA: Hypoglycemia · MedlinePlus: Blood glucose test

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.