This is the 2nd installment of my “ Breathing, the mini series“. This one is more for the non-asthmatics out there, but I think some of our lung challenged friends might learn a thing or two as well.

If you hang around asthmatics or browse as many personal asthma blogs as much as I do, then you’ve undoubtedly stumbled across phrases or symbols like “Green Zone” “ Yellow Zone” Red Zone”… Pfs and the like. To the lay person, these terms might just sound like a flowery way for an asthmatic to describe how they’re breathing at a particular time. In many cases however, these terms are not only used as subjective representations of how an asthmatic might characterize their breathing, but they also represent actual physical measurements from a device used to measure lung function.

Most of us ( if we are wise) use a simple, but accurate tool called a peak flow meter to measure our basic lung function. Peak flow meters work by measuring how fast one can exhale a single full breath. The test result is usually displayed in (lpm) liters per minute and is surprisingly accurate if done correctly. The resulting value, usually a number between 300-600, gives us an accurate reflection of how constricted or obstructed our lungs might be at that moment. The lower the number is, the more obstructed your lungs are and the more difficult it is to breath. The higher the number, the less obstructed and the easier it is to breath.

Because lungs come in difference sizes, shapes and genders, peak flow numbers and ranges will be slightly different for each person. What might be a normal peak flow value for one person, might be an abnormal value for someone else. Normal predicted values are based on age, height , weight and sex, but all this is not important. What is important, is that you determine what your peak flow number is when you’re feeling at your best. This is called your personal best or baseline peak flow . This is the number by which all other peak flow comparisons are made.

Your personal best pf is determined by taking a measurement when you’re breathing at your very best, preferably averaged over several weeks and with no symptoms and /or after taking an inhaler or nebulizer treatment.

The next thing we do is mark our peak flow zones: Peak flow zones are based on your personal best peak flow number. The zones will help you monitor your asthma and take the right actions to keep it under control. The colors used with each zone come from the traffic light ( which btw yours truly made popular).

The result will look something like this:

Green Zone (80 to 100 percent of your personal best) signals good control. If you take daily long-term control medicines, keep taking them.

Yellow Zone (50 to 79 percent of your personal best) signals caution: your asthma is getting worse. Add quick-relief medicines, as spelled out in your written asthma action plan. You might also need to increase other asthma medicines; ask your doctor.

Red Zone (below 50 percent of your personal best) signals medical alert! Add or increase quick-relief medicines according to instructions in your action plan and call your doctor or go to the ER right away.

Here are my personal peak flow zones: (Over the years my personal best pf has dropped from 550 to 350)

Green Zone 300 or greater

Yellow Zone 299-210

Red Zone 209 or less

So why do you need a medical device to tell you if you’re short of breath? Well, believe it or not, there are some asthmatics out there ( myself included), who are not always aware of subtle changes in their breathing. We’re known as poor- perceives or under-perceivers. For us, using a peak flow meter on a regular, and sometimes frequent basis, is crucial for getting a better handle on what’s actually going on with our lungs.

On the opposite end of the spectrum you have what they call over-perceivers. These are folks who are extremely sensitive to even minute changes in breathing pattern. These people should use their peak flow meter to verify whether what they’re feeling is actually being reflected in their peak flow readings. They’re are times when you can feel like and elephant is sitting on your chest, only to find that your peak flow readings are completely normal or just a little off. That’s because our brain and lungs are sometimes not on the same page. This mismatch in sensation vs PF readingx can also occur when the smaller airways are constricted or there is air trapping present, as PF readings are more reflective of large airway function than of the smaller airways.
Most asthmatics fall somewhere in the middle, and for them peak flows are usually done on an as needed basis or when they have symptoms.

Well, there you have it. The next time you hear an asthmatic talk about their breathing zones, hopefully you’ll have a better idea of just what the heck they’re talking about….yellow, green , red.. and all those weird zony things.

If you’d like to learn more about the asthma zones, in particular the yellow zone, check out this post I wrote a few years back.

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18 thoughts on “Asthma Breathing Zones

  1. Hey, I see your tri-coloured rainbow-meter is back. [Anddd, I'm glad to see you got out for a walk :-)]

    I'm gonna be passing this along to some of the people who've been on the receiving end of my lung-jargon–specifically, my coworker who's been checkin' up on me after those breathing-shenanigans after the walk.

    Great post, Epic Steve!

  2. Great blog post. I think it has alot of useful information. The last line made me laugh because I remembered my sister commenting on my peak flow meter, and how I describe my breathing in colors. She’s now a pro thanks to me. Once when I was short of breath, she said: are you yellow or orange??? or whatever colour it is when you’re not feeling good!
    That , and my little cousing asking if she can play with my toy gave me some laughs.:D

  3. We don't really comment in colours here. My docs use percentages-I once said in a clinic appt that I was fed up of being stuck in the yellow zone, and he looked at me very strangely.
    I'm wanting to recalibrate my colour zones now. My Green is 280 and above (PB of 360 in 2004/5) and I'm so rarely up in the green, Am I destined for a life of yellowness, although this morning I've blown a 70% and that feel much better than yesterday's 64%

    Fantastic about your 5000 miles. What does that average a year-it's amazing!

  4. First congrats on the 5oooth mile but a super congrats for getting to that all heralded green zone!!!! Great post too about zones. I find i have different parameters for how i am doing. Like when I am relativly settled my pf parameters increase but when I am having an unstable patch and on a certain med regime my pf parameters are noramlly lower. it all very confusing but have a letter from my con explaining it all. Recently i have been bobbling along in the mid yellow zone with a pf of 270-280 pretty regualry with dips to the lower yellow and upper red periodically…normally when i am coming up to neb time!!!! x

  5. My personal best peak flows were 250 for many years, dipping lower when not doing well. Now I can get up to maybe 220 on my good days. I'm gradually emerging from a flare-up and they're bouncing between 150 and 200. I am one of those perceivers who start feeling "off" before it shows up in the peak flows….the dyspnea kicking in quicker while walking, for example before the peak flow dips. I don't know if it's exactly the same thing or as intense as what Stephen noted in today's "health-o-meter", but last night I had three episodes of sudden chest tightness that were all received with my handy Ventolin inhaler. I am on 10 mg of prednisone now, tapered down from 40 mg. I'm overall improved from the worst of this flare-up, but not out of the woods….

    1. Gayle, What type of flow meter do you use? One thing I forgot to note about peak flows reading( which I\’ll append today) , is that they are generally a reflection of the function of the larger airways, not the smaller ones where most inflammation and air trapping occurs. When you exhale forcefully and quickly, it\’s the larger airways that empty first, then the smaller.
      So , in people with really chronic asthma, PFs don\’t always jive with subjective symptoms. A much more accurate test is FEV1 and FEV-25-75. Most non digital peak flow meters however, don\’t have this capability.

      I hope you can get back to baseline real soon 🙂

      1. Hi Stephen:
        Thanks for the in-depth reply and sorry you're having a tough time. I use both a low-tech non-electronic peak flow meter and also a Piko meter. Just now I took my piko measure and my PEF was 147 and FEV 1 was 66 (best out of 3 tries). The non-electronic gave me 210…which is pretty darn good right now. On a PFT test I took back in March, my FEF 25-75 % was 1.25 (predicted 2.26) pre-bronchodilator and 1.41 post-bronchodilator. I have similar results for the 25-75 test for many years…so suspect something amiss in the small airways. I always wonder if they are contracting/collapsing as I walk…causing me not to be able to speed up without running out of air/tightness/dyspnea…which than eases when I slow down the walking.
        Keep on keeping on!

        1. Hi Gayle, With numbers like that, you definitely have some small airway obstruction going on. If it it makes you feel any better, my baseline FEV 25-75 is only .32 ( or 9% of predicted). Right now as I type this response, it\’s only .25 or 6% of predicted.

          I think that what you are experiencing when you walk is either air-trapping or bronchospasm, or both. If your baseline pf is only 200, then you wouldnt have a lot of reserve to begin with. For you it\’s critical that you be symptom free, or as close to it as you can, before attempting any exercise.

          1. You guys are told so much info when you do lung function. I have no idea what my 25-75 is-possibly don't want to be told that either! It's all scary. I do know my LF is about 46%-last year it was 50% so this is not good info for me to hear. I actually don't even know what my predicted for FEV1 is, although, because I use a Piko meter I know what the value is. My PF is currently, 218, 60% of best (360) although that is an old 'best' and seems totally unreachable now. My FEV1 is 0.87 but again, I don't know the %age as I don't know my predicted there.
            I think there are a number of us currently suffering these prolonged bouts of extreme dyspnoea (sorry, uk spelling!) I think I'm having trouble because it is so rainy and damp here currently plus I'm trying to wean off the Pred quickly. 2nd day at 20mg, down from 30mg, and don't I know it. I'm calling it a day as I'm too puffed to do anything now and am propped up on the bed watching the Ryder cup!
            Feel better, GayleMyrna and Steve-I know you're bad again. Hugs x

            1. Sus, FEV1 is based on age, height , weight and gender. An FEV1 of less 1 liter is considered severe in just about any of those categories. PFTs are only one element in determining severity and prognosis. The others are , the ability to exercise and the general quality of life for the individual. Don\’t let the number get you down.

  6. Steve, I'm lovin' this series. I think EVERYONE with an asthmatic kid should be printing these posts out and handing them off to any friends or family members who babysit regularly. I know I would have, if these had been around when AG was little!
    (And congratulations!)

    1. Thanks Amy, I wish I had this stuff when I was kid. Heck, there weren\’t even peak flow meters when I was kid. Btw, did you know I was one of the people who came up with the original stop light system for the peak flow zones? ( Now I\’m really dating myself)

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