To better monitor and manage your asthma and understand how your asthma may change during the day or over a longer period of time, your health care provider may ask you to use a Peak Flow Monitor. A Peak Flow Meter estimates the Peak Expiratory Flow Rate, which is a measure of the fastest speed at which you can exhale the air from your lungs, after inhaling a big breath.

The measurement relates to how well the air is moving through the airways, so if asthma is present with airway inflammation or bronchoconstriction, the peak flow levels will be lower. Three peak flows are measured in succession and the best reading is recorded. This measurement can also be done before and after inhalation of your reliever medication.

The measurement is recorded daily or twice daily and written in a diary to help recognize changes in your peak flow that may occur during the day or over time. A decrease over time may show that your asthma is worsening and vice versa, an increase in measured values will indicate increased asthma control or response to inhaled controller medications.

Normal values for peak flow measurements are dependent on age, sex and height.  Each person will have his or her own best peak flow measures.  Based on the best peak flow, a decrease in peak flow may indicate a loss of asthma control so the patient can refer to their Asthma Action Plan for appropriate action.  Your Health Care Provider will review your measurements at follow up visits and assess your need for ongoing medications and updates to your Asthma Action Plan.

For more information about monitoring your asthma and available monitoring products click here.