Know Your Peak Flow

A peak-flow meter is a small device that measures how fast the air you breathe is moving out of your lungs when you exhale. You and your health care provider can use information from a peak-flow meter to help stop a flare-up in its tracks. When the airflow from your lungs is slower, this can be a sign of asthma problems. It can help alert you to problems hours or even days before you start to experience actual symptoms.

Ensuring accuracy

Peak-flow readings must be accurate to be useful. That is why it is so important to use your peak-flow meter the right way:

1. Before you take your reading, make sure that the meter indicator is at the bottom of the scale. 

2. Stand up and breathe in as much air as you can. 

3. Place your lips tightly around the mouthpiece with your tongue outside the hole. 

4. With one breath, blow out as hard and as fast as you can. 

Finding your best reading

Your provider can help you find your best reading. This must be done when your asthma is under control, and it should be recorded over a few weeks. You’ll compare all future readings against the best reading.

Ask your provider exactly when to take readings. You will likely need to do it daily, as well as when you have a flare-up. Be diligent about taking readings and recording them.

At every office visit, review your peak-flow-readings diary. Know what medicines to take when you get a reading within a certain range.


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