The comparison between Blood Glucose Monitoring (BGM) strips and Continuous Glucose Monitoring (CGM) centers on the physiological difference between capillary blood and interstitial fluid (ISF). While BGM strips provide a near-instantaneous measurement of systemic glucose, CGM readings are subject to a 5–15 minute physiological lag, making them less accurate during periods of rapid glucose flux (e.g., post-exercise or post-prandial).

Technologically, BGM relies on single-use dry-reagent amperometry governed by ISO 15197:2013 standards (requiring ±15% accuracy), whereas CGM uses multi-day wired enzyme filaments measured by MARD (Mean Absolute Relative Difference). Although modern CGMs have achieved MARDs under 9%—rivaling strip accuracy—they remain susceptible to bio-fouling, compression artifacts, and sensor drift. Consequently, while CGM is superior for tracking trends and Time in Range (TIR), BGM strips remain essential for verifying outliers, calibrating sensors, and confirming hypoglycemia when symptoms contradict sensor data.