Level 1 hypoglycemia
Also called level 1 low, low, mild hypoglycemia.
Level 1 hypoglycemia is glucose under 70 mg/dL (3.9 mmol/L) and at or above 54 mg/dL (3.0 mmol/L). It is the alert level: low enough to treat, above the line where confusion and other brain symptoms usually begin. On an AGP report it is the Low band. (ADA Standards of Care 2026, section 6; International consensus on time in range, 2019)
Target
Time under 70 mg/dL (3.9 mmol/L) below 4% for most adults, about 1 hour a day. (ADA Standards of Care 2026, section 6)
Worked example
A glucose of 62 mg/dL (3.4 mmol/L) is level 1. A glucose of 54 mg/dL (3.0 mmol/L) is still level 1; 53 mg/dL (2.9 mmol/L) is level 2.
Related terms
Sources, quoted
- ADA Standards of Care 2026, section 6: “Level 1 hypoglycemia is defined as a measurable glucose concentration <70 mg/dL (<3.9 mmol/L) and ≥54 mg/dL (≥3.0 mmol/L).”
- ADA Standards of Care 2026, section 6: “Level 2 hypoglycemia (defined as a blood glucose concentration <54 mg/dL [<3.0 mmol/L]) is the threshold at which neuroglycopenic symptoms begin to occur and requires immediate action to resolve the hypoglycemic event.”
- International consensus on time in range, 2019: “In the AGP report, glucose ranges are defined as “Very High” (Level 2), “High” (Level 1), “Low” (Level 1), and “Very Low” (Level 2).”
- ADA Standards of Care 2026, section 6: “A goal percent time <70 mg/dL (<3.9 mmol/L) of <4% (or <1% for older adults) and a goal percent time <54 mg/dL (<3.0 mmol/L) of <1% are recommended in people using CGM to prevent hypoglycemia.”
Every quote above is checked against its source page before each update of this site; last checked 2026-10-06. The worked example is our own arithmetic. This page explains a term; it is not advice for a person's treatment.