one set of lungs brags to another set of lungs. They are next to a peak flow meter.

"What's Your Personal Best on Your Peak Flow? Hmmm?"

"What's your personal best on your peak flow? Hmmm?" This was the start of a conversation I overheard between my older son and my daughter. Of course, my daughter had to roll her eyes. I can interpret that eye roll to mean "stop talking and go away."

I have a family of 5, all 5 of us have allergies, and 4 of us have asthma. For the last 20 years, our life and conversations have revolved around allergies and asthma. Sad, but true.

What is peak flow?

So what were my kids talking about? What is a peak flow, and what does it have to do with asthma?

A peak flow meter is a small handheld device that measures how much air you can blow out in 1 second. For it to work well, you have to blow hard and fast! If used right, a peak flow meter is a good tool to use to see how your lungs are doing.1

Each person will have a "personal best" or a "high score." Like an Asthma Action Plan, you will have green, yellow, and red zones.1

How peak flow works

  • Green zone is between 80 and 100 percent
  • Yellow zone is between 50 and 80 percent
  • Red zone is less than 50 percent

As an example, if your personal best is 500, your green zone would be between 400 and 500. That's your "normal range." Your yellow zone would be between 250 and 400. And your red zone would be anything less than 250.

Why do peak flow scores vary person to person?

Why? Well, size matters – as does your sex. A child will have a lower reading than an adult (because kids naturally have smaller lungs). Additionally, men typically have bigger lungs than women. Who knew?! This can be a random trivia point you can use to astonish and amaze people. Ha!2

Using a peak flow meter (we just call it a peak flow) can help you monitor your lungs. For our family, our peak flows were literally lifesavers. With 12 hospitalizations for my kids, the peak flow would give me advanced warning that my kids were getting sick and their airways were swelling. Their peak flow would start to drop, and then 2 days later, the running nose and coughing would start. I knew that meant we were in for a rough couple of weeks. I would call the asthma doctor, and he would adjust my kid's medications, listen to their lungs, and see if they needed to be admitted to the hospital.

Featured Forum

View all responses caret icon

Why regularly test peak flows

My kids' asthma had a habit of going from bad to worse very quickly, so peak flows were mandatory at our house every morning and night. Each kid would blow into their peak flow and yell out their number. I knew each of my kids' numbers, and I could hear how their lungs were doing by listening to them exhale hard and fast.

My middle son had the most severe asthma and would yell out his number. When he was little, he would yell "350!" each morning before he had breakfast. Some days, I could tell he was a little off, and he would yell "275!" I could hear that his lungs sounded weaker. In fact, his voice would also sound higher and tighter. He would try his peak flow again, but could not get past 275.

So, was he faking it so he did not have to go to school? Peak flows are "effort dependent," meaning you have to use it right. Some kids can try to fool their parents and doctors by blowing softer than normal. My kids never did that. They missed so much school being sick at home, or in the hospital, that they wanted to be normal and go to school with their friends. They hated missing school!

Talk to your doctor

If you do not have a peak flow meter for your asthma, talk to your doctor about getting one. There are many different types and prices, so find what you like.

As for my kids' conversation: of course, my older son had a much higher peak flow than his sister because he is bigger and he is male. And he does because he plays the bagpipes!

By providing your email address, you are agreeing to our privacy policy.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

Join the conversation

Please read our rules before commenting.