A peak flow meter is a device that measures how quickly air can flow out from your lungs and tell you how open your airwats are. Be sure to write down your results and take them with you when you visit your doctor. A lung function test every clinic visit will tell you how well your treatment plan is progressing.

STEP ONE
Move the marker to "0" or to the lowest point/position on the scale. It is best to stand but if you can't stand, be sure to sit up straight. Ensure you're in the same position each time you test.

STEP TWO
Take a deep breath as you put the mouthpiece of the peak flow meter in your mouth between your teeth. Close your lips tightly around it. Be sure your tongue does not block the opening. Blow into the mouthpiece once, as hard and as fast as you can.

STEP THREE
Take the peak flow meter out of your mouth. Look at the marker. It will have moved along the numbered scale. Write this number down. Move the marker back to "0" or to the lowest point/position on the scale.

STEP FOUR
Repeat the test two more times.

STEP FIVE
Write the highest of the three numbers on your chart or in your diary. This is your peak flow result.