BloodGlucoseValueUnderstand every reading

Blood glucose 45 mg/dL — what does it mean?

45mg/dL2.5 mmol/L
  • Without diabetes, fastingVery low
  • Without diabetes, 2 h after eatingVery low
  • With diabetes, before a mealLevel 2 hypoglycemia
  • With diabetes, after a mealLevel 2 hypoglycemia
  • In mmol/L2.5 mmol/L

Treat a low now

  • Take 15–20 g of fast sugar: 4 glucose tablets, ½ cup (4 oz) of juice or regular soda, or 1 tablespoon of sugar or honey.
  • Re-check after 15 minutes. Still below 70? Repeat. Once above 70, eat a snack or meal.
  • If the person cannot swallow safely, is confused or unconscious: give glucagon if available, put them in the recovery position and call 911 (US) or your local emergency number. Never put food in the mouth of someone who is unconscious.

If you don't have diabetes

45 mg/dL is well below normal. In people without diabetes, blood sugar rarely falls this low; if the reading is real and you have symptoms (shakiness, sweating, confusion), treat it with fast sugar now and see a doctor to find the cause.

Fasting (8+ hours without food)

Very lowScale with 45 mg/dL marked5510012645 mg/dL

2 hours after eating (or glucose tolerance test)

Very lowScale with 45 mg/dL marked5514020045 mg/dL

If you have diabetes

45 mg/dL is level 2 hypoglycemia — clinically significant low blood sugar. Treat it immediately (see below). If it happens repeatedly, your treatment plan needs to change.

Before a meal / fasting

Level 2 hypoglycemiaScale with 45 mg/dL marked548013118124130045 mg/dL

1–2 hours after a meal

Level 2 hypoglycemiaScale with 45 mg/dL marked5418024130045 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.

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 45 mg/dL that means roughly 38–52 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.