What is the blood glucose threshold defining hypoglycemia?

• A. At or below 60 mg/dl
• B. At or below 50 mg/dl
• C. At or below 70 mg/dl
• D. At or below 40 mg/dl

Answer: (B)

Hypoglycemia is a state where blood sugar falls low enough to risk impaired brain function. In this context, the defined threshold is 50 mg/dL or below. This cutoff provides a clear, actionable point: it reliably indicates when glucose is too low to meet the brain’s needs and warrants prompt treatment to prevent neuroglycopenia. Levels higher than this can be variable—some people may have symptoms at higher levels, while others tolerate them fine—so using 50 mg/dL standardizes guidance and reduces unnecessary alarms. While many medical references cite <70 mg/dL as hypoglycemia, this specific standard uses 50 mg/dL as the practical threshold for intervention.