What is the normal range for blood sugar levels?
May 28, 2025
Source: Cainiu Health
Dr. Liu Feng
Introduction
Blood glucose levels are influenced by food intake, hormone secretion, and individual metabolism. Fasting blood glucose reflects the basal insulin secretion function; if it consistently exceeds 6.1 mmol/L, it may indicate impaired glucose regulation, and an oral glucose tolerance test should be performed for further evaluation. Postprandial glucose peaks are related to carbohydrate intake; levels exceeding 11.1 mmol/L may indicate diabetes.
Under normal circumstances, the normal range for fasting blood glucose is 3.9-6.1 mmol/L, and postprandial (after-meal) blood glucose two hours after eating should be ≤7.8 mmol/L. If concerned, it is recommended to seek medical advice in advance. Detailed analysis is as follows:
Blood glucose levels are influenced by food intake, hormone secretion, and individual metabolism. Fasting blood glucose reflects basal insulin secretion function; if consistently exceeding 6.1 mmol/L, it may indicate impaired glucose regulation, and an oral glucose tolerance test is recommended for further evaluation. Postprandial glucose peaks are related to carbohydrate intake; levels exceeding 11.1 mmol/L may indicate diabetes, while values between 7.8-11.1 mmol/L fall within the range of impaired glucose tolerance.
Blood glucose levels may fluctuate due to stress, infections, or medication interference. For example, increased adrenaline secretion can temporarily elevate glucose levels, and beta-blockers may affect sympathetic nervous system regulation. Reference ranges may differ for elderly individuals, pregnant women, and children, requiring comprehensive assessment based on age and physiological status.
Blood glucose monitoring should be conducted under standard conditions: fasting measurements require 8-12 hours of fasting, and postprandial testing starts timing from the first bite of food. Abnormal results should be confirmed with clinical symptoms and repeated tests to avoid misinterpretation from a single measurement.
