Question: How Does Peak Flow Relate to My Asthma Action Plan?
Answer: A peak flow meter is a tool for testing how your asthma is doing, whether its getting better or worse, or staying about the same.
With your doctor's help, you can use your peak flow readings to figure out what zone you are in, and then what action steps to take, if any.
What does this mean? When we talk about asthma control, we classify the level of control into 3 zones, which can be thought of like a traffic light. Here are some general guidelines on the 3 zones:
Green Zone. Like a traffic light, green means "you are good to go" (continue as you have been). When your peak flow reading falls within 80 to 100 percent of your personal best PEF rate, then you are in the green zone. That means your asthma is probably under control, and you can continue with your usual asthma treatment routine.
Yellow Zone. Yellow means caution, and when your peak flow rate falls only within 50 to 80 percent of your personal best, you are in the yellow zone. You need to check your asthma action plan to decide what action to take. Being in the yellow zone means your airways are narrowing and you may need to use your quick-relief inhaler or take other steps.
Red Zone. When it comes to asthma, being in the red zone means "danger." When your peak flow rate is less than 50 percent of your personal best, you are in the red zone. You need to take action right away to prevent or stop a full-blown asthma attack from occurring. Using your quick-relief inhaler and a call to the doctor are in order. Emergency care may even be needed. Let your asthma action plan guide you.
How your zones are defined on your personal asthma action plan may vary.
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