peak flow

just out of curiosity what are peoples best and worst peak best is about 300 and worst ive had was about 75(was very ill that time but didnt realise it), when it drops with an attack the doc told me contact the asthma team or gp if it goes under 200 and get to casualty if it drops under 150...if i did this every time i would constantly live there so i try to manage at home....what about everyone else?

32 Replies

  • Hi Jay

    My best is about 500, normal peak flow for me is about 450. If mine goes under 350 I have to go to A&E or the Doctors.

    My peak flow was 300 last week as I had a bad chest infection but it is back up to 440 today :-)


  • wow, that is low.

    My best is 530 and my lowest is 390 but I only have mild asthma.

    I have no idea at what level I should worry about it, don't have an action plan, just take my reliever if I feel breathless/tight chest etc.

  • fao september: it might be a good idea for you to keep a diary to see how your peak flow changes throughout the day (mine drops early morning and late evening and thats when im not too ill), that way you will be able to see what is definately good for you so that you can tell when you may need help cos its an individual action plan that is needed rather than what others flow is like x

  • OMG 75 is really low.

    personally my best is officially 758 but have done 900+ and the lowest not seen since diagnosed thankfully was 280.

    Currently low 600's but thats fine with me, anything below 550 and I really notice it

  • Thanks Jay will do, think mine seems worse through the day though, seems better first and last thing xxx

  • My best is 550 and my peakflow at the moment is 280 but docs dont seem to worry about that, keep going by my old results in 2004 which were at best 350!

  • My best is 550 but for last few weeks its been 350-440..... worst was 20 I was forced to do it when i knew it be rubbish then they put me to sleep after that! During last attack was 200

  • Everyone is so different. Years ago I had a pf of 800 (they couldn't believe it and called me a ""horse lung"" lol) but that's changed now as asthma got worse. Best pf was still 650 up to recently but just a couple of weeks ago my asthma nurse revalued my personal best down to 550 now, which looks great on the average chart for pf's but then I know what I was capable of in the past:-/

    she said that it can change and that's why it's important to keep a pf diary so that you know where you stand.

    Love Lydia x

  • Peak flow also goes on your BMI which makes everyone different. Definatly keeping a peak flow diary I have one I have to write my peak flow in also how many times that day I use my ventolin inhaler also symptoms I have been getting like coughing etc. Ask your asthma nurse/gp surgery for a peak flow diary I got given mine via the asthma nurse.

  • Peak flow predicted values go on age and height not bmi. As we age its suppose to drop according to the predicted charts! Everyone is different though. What is good for some may be bad for others. Personal best PF is what everyone should aim for it i went by my predicted value id forever be in a+e.

  • my pf drops after every asthma exacabation currently personnal best is 270 for month of june, 330 for may and in october it was 390. i maybe only get personnal best a few times a month. if i drop to 250 or less im gubbed. currently sitting at 270 and thats after an exciting weekend and iv mag sulphate and prednisolone 40 mg..... there goes the exbanding waist band again

  • something I found last night by accident and thought it appropriate for here.

    Did you know that the average person reaches peak respiratory function and lung capacity in their mid 20's? Then they begin to lose respiratory capacity: between 9 and 25% for every decade of life! So, unless you are doing something to maintain or improve your breathing capacity, it will decline, and with it, your general health, your life expectancy, and for that matter, your spirit too!


  • My best is 480 and the worst unrecordable! I think that peak flows under a 100 aren't particularly accurate. Over the last few weeks it has been varying between 230 and 450. I have been trying to identify and patterns.

    I agree if I followed that advice I would be constantly at A&E or the GPs. Maybe next time you see the doctor ask if you can have a more realistic plan (show them your peak flow chart if you have one). I know the feeling of struggling at home.

  • Think I'll take up the bag pipes .... Will get the pf up i suppose

  • my best is 550 but lowest is 300 and then I Struggle lots.

  • My best is 540, when well I usually get around the 490-520 mark, my worst (recorded) is 120. Because I drop really quickly, anything below 400 and it's off to the docs, which can be a problem if I see someone who doesn't know my asthma and thinks that's a great PF.

    What's interesting to me is that a lot of the replies here. going by what I can gather about your gender/age (obviously don't know heights), give best PF above average/expected values. It's always a problem I have if docs insist on using expected values as this doesn't reflect me or what's happening to me.

    How do others' PFs compare with expected values? Do you have problems if your usual is higher than expected so a drop doesn't look bad by the expected charts, but actually is?

  • Ratty, you have hit the same problem I've encountered, my best is over 100p/min above the top end of predicted, but during the winter I can have symptoms and be in the middle of predicted (580) and the doc used to say thats fine. It's not for me though and I do have days in the winter especially if I'm not well when that for me is a real issue.

    I wonder how the predicted values were calculated, because if were supposed to have crap lungs and these predicted values are based on normal healthy lungs, then why do so many exceed the top end of predicted, and I'll refrain from suggesting it's down to over medication.

  • re the messages.....i kept a peak flow chart for a long time to determine my best and worst so that i knew when to get serious help or manage at home, although sometimes i am taken unawares when it drops suddenly. i def agree that peak flow drops as you get older and was told that a good way to keep exercising your lungs (for copd like but its prob same for asthma-i think!) is to blow up a balloon a couple of times every day.tried this but wasnt very good even as a kid but it might be good for some people. the doc at the hospital last night said that he could do a better peak flow than my best when he was having a bad attack, which i do understand what he was trying to tell me but he was quite tall and in his 20's and im little,fat and 40!

  • my predicted is 429, my best is 550 (570 during my spirometry test)

    Agree, where do they get the predicted values from, 429 stops me reading books to the kids!

  • PF being higher than predicted

    Ratty I am the same. My best peakflow is 550 but according to the 'normal' predicted charts for my age and height should be around 440.

    So for me a drop down to below 300 and I am feeling very unwell, and if it's been going much lower than that have to be on steroids / daily nebs etc. But when having symptoms and peakflow is around 400 they're like oh thats not too low, but least now I know to make sure they know what my best pf is. Charting it helps so that they can see the peakflow trends.

    This weather is pants, this morning was 280 with inhaler not bringing it up so nebbed and then went up to 410. I don't know what my lowest reading is because i've been too unwell to be able to take it, but for me being below 300 after nebbing is my point where i have to get to hospital and get some more help.

    I wonder if some of it is as asthmatics we are old hands at measuring peakflows and that our technique for it is better, that we do it properly and that is why it's higher than many charted predictions. I know with my mum she's got v mild asthma and if she does her peakflow its awfully low, but with no symptoms and feeling fine, when i see her do it it's more like as if u were gently blowing out a candle, just because she's not used to doing it, but if i show her how to do it and get her to do it properly then it's about 3 times as high as her first attempt. Does that make any sense or is it just a random thought i had??


  • You're all so right! It has annoyed me so many times when docs said ""that pf is fine"", it's like saying ""there's nothing wrong with you""!

    I noticed recently (in our area at least) that I was asked about my personal best. Not all ask for it but I definately noticed a bigger change in that matter.

    Gonna do some research as to how these pf charts have been calculated. Should be interesting.


  • mine has just gone to 220,best 550 got to get some help, Son's is down to 300, best 400 so we both need the nebuliser, he comes 1st.He is in severe pain and his breathing is really weird, it just proves, peak flow isn't every thing, trust your instincts.Off to docs later

  • Today im at home with the combined asthma hayfever eurgh. and my peak flow is 390. yet sometimes it can be 350 and i will feel fine? peak flow doesnt always make sense.

    My worst is 320 and my best is 450. But the doc thinks if i keep on step 3 after the hayfever season i should reach the 500's. a figureway above the predicted 420 for someone whose my height and age.

    peak flows do confuse me.

  • I'm the same as many of you.

    For me, ""normal"" is 550. Best is nearly 600. So I've started explaining it to doctors and hospital staff in terms of percentages or drops. So my diurnal variation is over 200 at the moment, and I'm only getting 85% of normal. It was a suggestion from my asthma nurse, based on the American model. 80-100% and you're in green; 60-80% needs steroids; under 60% means get help asap.

    Stops them getting quite so hung up on ""but your PF is 400. you're fine!""

    A PF of 400 stops me doing a lot. A PF of 300 is technically in my red zone.

  • Hi, I'm newly diagnosed, my PF when I first went to the Drs was 250. Since then I've managed 460 once, but at the moment I'm averaging about 410. I think my predicted is around 430. Over the last couple of years my health checks at work showed my PF at 480 so hopefully I can get back there.


  • It's good to know I'm not the only one with a higher than predicted PF which then causes problems as drops don't look significant by predicted values. It has helped that my consultant has written by best PF on my protocol and the A&E docs or paramedics do tend to follow this now. The only major problem I've had of late was a terrible locum doctor who thought she knew better than my consultant...

    Interesting theories about why so many of us might be better than expected (anyone yet found out where the numbers came from - do they need updating perhaps?). I have another one. I, and I think others here were, before asthma (and still are when possible) reasonably or very fit, I was definitely very active before my asthma became bad and I still do what I can (and push myself a little too hard) which may mean we have stronger/fitter lungs - maybe? Perhaps someone who has always been unfit, never exercised etc. would not see a doctor with what we would know to be asthma symptoms as that may be 'normal' for them?? Maybe, we're just a mis-representative sample? Maybe I've confused myself!!

  • Lots of interesting posts. I am feeling left out that my best is not better than predicted though!

    Ratty makes a good point that us asthmatics might be more practiced at doing peak flows. My dad is a GP (and not asthmatic) and regularly measures his peak flow and his is way above predicted. Maybe we should get non-asthmatic friends and family to regularly measure their peakflows and see if they increase with practice.

    I think the predicted values are based upon the results of a large sample of people. There will be a spread of values around the mean so logically some people's best will be above or below the mean.

  • My best peakflow is 350 although I have not managed to get to that for several months just recently my peakflow varies between 250 and my lowest peakflow is 120

  • i'm going to agree with Ratty on why we have higher PF's than predicted. Most of us tend to be fitter to a degree and if you read the reports that a higher proportion of athletes have asthma than the general population, is it simply that everyone else is less fit and the couch potato group may have asthma but not know it, after all they'd be so unfit that just getting up would leave them breathless (well maybe not quite) but that idea.

  • Best Peak Flow

    I had my annual Asthma Clinic check up and I managed to get my personal best, i achieved 500, even the asthma nurse was impressed as this is above my predicted peak flow.

    I had taken my Symbicort 200/6 2 puffs, my ventolin inhaler 2 puffs and my atrovent inhaler 2 puffs,30 minutes prior to my appointment, so she said i had cheated.

    I said i was struggling with the heat so have had to use my ventolin inhaler more than usual, she said once i have settled down, then i can reduce my symbicort down to 1 puff twice daily and see how i go, i am hoping to be able to reduce my other inhalers too at the next review.

    This is brilliant news for me as last year i had such a rough time with my asthma.

  • bumped for Gareth

  • I'm the opposite my peak flow is that low even the smallest drop can indicate a bad flare up. But usually my symptoms are already showing before a drop occurs. Ps I'm an enforced couch potatoes these day tho did cycling and gym but that feels like a past life now !!

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