Impact of Hydration Status on CGM Signal Integrity

The Connection to Accuracy

Hydration status can significantly affect CGM sensor performance and accuracy.

How Dehydration Affects CGMs

Physiological Impact

• Reduced interstitial fluid volume
• Altered glucose diffusion rates
• Concentrated glucose readings (potentially false highs)

Signal Quality

• Increased signal noise
• More erratic readings
• Potential sensor errors

Research Findings

Studies indicate that hydration status impacts sensor performance:

• Well-hydrated users show more stable signals
• Dehydration can cause false readings
• Rehydration typically restores accuracy

Practical Recommendations

For Accurate Readings

• Maintain consistent hydration
• Be aware of readings during dehydration (illness, exercise, heat)
• Don't make major treatment decisions when dehydrated

During Exercise

• Pre-hydrate before activity
• Continue hydration during prolonged exercise
• Expect some signal variability

During Illness

• Monitor hydration carefully
• Confirm CGM readings with fingersticks if dehydrated
• Seek medical care for severe dehydration

Manufacturer Guidance

Most manufacturers recommend adequate hydration for optimal sensor function, though specific guidance varies by device.