Thought Archive

Diabetes

Continuous Glucose Monitors (CGMs) vs Finger‑Prick Testing

18 Aug 2025 • Updated 21 Aug 2025

Continuous Glucose Monitors (CGMs) vs Finger‑Prick Testing

Continuous Glucose Monitors (CGMs) vs Finger‑Prick Testing

What CGMs do well

  • Trend arrows, alerts, and overnight data.
  • Reduce finger‑pricks and help spot patterns.

Known limits

  • Lag time: interstitial glucose can trail blood glucose.
  • Compression lows; sensor warm‑up periods; occasional sensor error.

When to confirm with a finger‑prick

  • Symptoms don’t match CGM.
  • Before driving if uncertain.
  • During rapid changes (exercise, after treating a hypo).
  • When calibrations/confirmations are recommended by your team.

Practical tips

  • Set high/low alerts thoughtfully to avoid alarm fatigue.
  • Rotate sites; follow clean insertion technique.
  • Have a backup meter and strips available.