How you prepare

Work with your doctor to make sure you get the right type of peak flow meter. Peak flow meters are available over-the-counter and can be purchased at a pharmacy. There are several types of peak flow meters available, and all of them work basically the same way: You blow a fast, hard breath into a mouthpiece and record the resulting score.

For the most accurate reading, be sure your peak flow meter is clean and, if applicable, fully charged.

Using your peak flow meter

Here's the correct way to use a peak flow meter:

1. Move the marker to the bottom of the numbered scale, and connect the mouthpiece to the peak flow meter (if it isn't already connected).
2. Stand up if you're able.
3. Take a deep breath, filling your lungs completely.
4. Place your lips tightly around the mouthpiece. Blow as hard and as fast as you can with a single breath.
5. Note the final position of the marker. This is your peak flow rate.
6. Follow the steps above, then blow into the peak flow meter two more times. Record the highest reading of the three.

To get accurate readings, make sure you know how to use your peak flow meter properly. Ask your doctor or other health care professionals to watch you use it. It's also important to keep your peak flow meter clean. Follow the manufacturer's instructions — most peak flow meters require weekly cleaning with warm water and a mild detergent.