Whenever your peak flow numbers start to fall into the yellow or red zones, you may also need to see your healthcare provider to discuss changes to your treatment plan.

Yellow zone refers to 50-80% of normal peak flow and cautions that asthma is getting worse. Red zone indicates less than 50% of normal peak flow and warns about an upcoming asthma attack and the ...

Peak flow meters are inexpensive (the average price is around $15 to $20), handheld, and easy to use. You simply blow as hard as you can into the device and it will measure your air flow rate in ...

PEFR stands for peak expiratory flow rate. It's a test that measures how fast you can exhale. Learn more about PEFR, why your doctor may suggest this test, how to prepare, what to expect, and ...