A peak-flow meter enables you to measure day-to-day variations in your breathing and lung capacity.

‌As you use the peak flow meter, you'll start to notice breathing patterns, including your personal peak flow. This is the highest reading out of three on your peak flow meter.

The peak flow meter is a simple device for measuring how quickly you can blow air out of your lungs. It's a rough measure of the amount of narrowing of your airway and hence it can be used to ...