As someone with asthma, you know how important it is to monitor your condition. You need to know how well your lungs are "working": is their ability to move air in and out staying the same, or is it getting better or worse?
When you monitor your asthma, you can control it. When you control your asthma, you also control your life—you do what you want to do, and your asthma does not limit you.
Measuring your peak expiratory flow is an important part of monitoring your asthma.
Peak expiratory flow (PEF) measures how fast you breathe out when you try your hardest. It tells you how well your lungs are working. You measure PEF with a peak flow meter, an inexpensive device that you can use at home.
You measure PEF as litres of air per minute.
How often you measure your PEF depends on how severe your asthma is and how often you have asthma attacks. If you have severe asthma or cannot tell when you are having asthma symptoms, you may need to check your PEF twice a day, in the morning and in the evening. If you have mild asthma, you may not need to check your PEF daily and can instead monitor it by paying attention to symptoms. However, if any asthma symptoms develop, you may need to check your PEF. Talk with your doctor about how often you check your PEF.
What does PEF measure?
PEF measures how fast you breathe out when you try your hardest. It tells you how well your lungs are working.
PEF measures how fast you breathe out when you try your hardest. It tells you how well your lungs are working.
PEF measures how fast you breathe out when you try your hardest. It tells you how well your lungs are working.
Measuring your PEF is important, because it lets you:
Measuring your PEF can help you know if you may have an asthma attack.
Measuring your PEF can help you know if you may have an asthma attack. It also helps you determine your asthma zones, identify triggers, and measure changes in your breathing.
Measuring your PEF can help you know if you may have an asthma attack. It also helps you determine your asthma zones, identify triggers, and measure changes in your breathing.
If you have never used a peak flow meter, talk with your doctor about how to use it correctly, and then practice using it.
Measure your PEF routinely. Check your breathing regularly, even if you are feeling good. PEF is lowest in the early morning and highest in the afternoon. When you measure your PEF once a day, it needs to be done first thing in the morning before you use your asthma medicine.
It's very important to record the results of your PEF measurements in your asthma diary. This will help you measure changes in your breathing. Take your asthma diary with you when you see your doctor so you can review it together. It's very important to review the diary with your doctor whenever you feel your lung function is getting worse.
Remove any gum or food you may have in your mouth. View a slideshow of how to measure your peak expiratory flow. Repeat the steps two more times. After you have blown into the meter three times, take the highest number you received, and write it in your asthma diary or on another record sheet.
If you cough or make a mistake during the testing, do the test over.
Different brands of meters may give different values for results. If you change meters, you will need to determine your asthma zones using the new meter.
Note: If your best effort is in your red zone, take your relief medicine immediately and call your doctor or go to the emergency room.
When you measure your PEF once a day, it needs to be done first thing in the morning before you use your asthma medicine.
Talk with your doctor
If you would like more information on asthma, the following resource is available:
Allergy/Asthma Information Association (AAIA) | |
295 The West Mall, Suite 118 | |
Toronto, ON M9C 4Z4 | |
Phone: | 1-800-611-7011 (416) 621-4571 |
Fax: | (416) 621-5034 |
Email: | admin@aaia.ca |
Web Address: | www.aaia.ca |
The Allergy/Asthma Information Association (AAIA) provides information and education materials for Canadians with allergy and asthma. | |
Asthma Society of Canada | |
130 Bridgeland Avenue | |
Suite 425 | |
Toronto, ON M6A 1Z4 | |
Phone: | 1-866-787-4050 toll-free (416) 787-4050 |
Fax: | (416) 787-5807 |
Email: | info@asthma.ca |
Web Address: | www.asthma.ca |
The Asthma Society of Canada provides information and education programs for Canadians with asthma and supports asthma research. | |
Canadian Lung Association | |
3 Raymond Street | |
Suite 300 | |
Ottawa, ON K1R 1A3 | |
Phone: | 1-888-566-5864 (613) 569-6411 |
Fax: | (613) 569-8860 |
Email: | info@lung.ca |
Web Address: | http://www.lung.ca/ |
The Canadian Lung Association focuses on research, education, and the promotion of respiratory health. The organization offers educational information on a variety of diseases and environmental threats, as well as information on research, support groups, and resources for children and teachers. Call to find a local office in your area. | |
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Last Revised: May 11, 2012
This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.