Before measuring
Readings can be inaccurate or delayed, sensors can irritate skin, and some over-the-counter systems do not provide urgent low-glucose alerts. Symptoms and treatment decisions may require confirmatory testing and clinical guidance.
A CGM samples glucose in interstitial fluid through a skin sensor and estimates glucose values and trends. Interstitial readings can lag blood glucose, especially during rapid change.
Purpose, evidence and practical considerations.
Readings can be inaccurate or delayed, sensors can irritate skin, and some over-the-counter systems do not provide urgent low-glucose alerts. Symptoms and treatment decisions may require confirmatory testing and clinical guidance.