A peak flow meter measures how fast you can push air out of your lungs. This tells you how well you are controlling your asthma. Measure your peak flow as many times a day as your health care provider tells you to.
Step 1: Move the marker to 0 or to the lowest number on the scale. Stand (If you can't stand, be sure to sit up straight). Make sure you're in the same position each time you test.
Step 2: Take as deep a breath as you can. Put the mouthpiece of the 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 & fast as you can.
Step 3: Take the meter out of your mouth. Look at the marker. It will have moved along the numbered scale. Write this # down. Move the marker back to 0 or to the lowest # on the scale.
Step 4: Repeat the test 2 more times. Write the highest of the 3 #s on your chart or in your diary. This is your peak flow number. Always measure your peak flow at the same time each day.
Info meant for educational purposes only & not as med advice -- seek MD attn ASAP.