Reviewed by David Tinkelman, MD

The following table shows an example of how these zones work. Your doctor can help you create a similar table for your own asthma.

Peak Zone Stoplight GreenGreen: 80-100% of your personal best

  • Your breathing is good.

  • You do not have any early warning signs or asthma symptoms.

    • Take all your medicines every day, as your doctor tells you.

  • Take your inhaler before exercise, as your doctor tells you.


Peak Zone Stoplight YellowYellow: Caution 60-80% of your personal best

  • Runny, stuffy nose.

  • Feel more tired.

  • Chin or throat itches.

  • Sneezing.

  • Restless

  • Red or pale face

  • Coughing

  • Dark circles under your eyes

  • Use "rescue" medicine

  • Recheck peak flows after 20-30 minutes

  • Call your doctor, healthcare professional, or nurse care manager:

    • if your peak flow is not back to the Green Zone

    • if your peak flow drops into the Yellow Zone again in less that 4 hours.


Peak Zone Stoplight RedRed: Danger Below 60% of your personal best

  • Cough, more at night

  • Wheezing

  • Chest feels tight or hurts

  • Breathing faster than normal

  • Get out of breath easily

  • Use your quick-relief medicine by inhaler or nebulizer right away!

  • Call your doctor or 911 NOW

BACK: Peak Flow Meter

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