Confused by peak flow reading!

Morning all I just wondered if anyone can shed on light on this for me? I have been studying my peakflow in readiness for a visit to a consultant. What I have noticed is that my peakflow can be as high as 360 and yet I still need to use my blue inhaler 8 times. However over the past few days it has been as low as 300 and I haven't struggled to breath and haven't needed to use the blue inhaler once! Has anyone else had this same experience? I am really confused now as the peakflow isn't going to be accurate to how I feel!

7 Replies

  • As you have a consultant appointment pending then it's probably worth discussing your peak flow records & how you feel, I don't think PF is by any means the be all & end all of asthma diagnosis (although it is obviously very important) & I know other people on here have reported feeling bad with high PF readings. Your consultant will be aware though of other factors in your lungs that might be affecting both symptoms & readings.

  • Thank you for your replyx

  • Hi

    You're peak flow naturally changes throughout the day (best is normally around 5ish in most people, worst in the morning pre-meds [well during the night but most of us are asleep then 😅😴]) which is why you get asked about symptoms you're experiencing as well.

    Everyone's best peak flow is different (so everyone green/yellow/red zone is different too) but if you're at/near your best PF and still experiencing symptoms it's definitely worth telling your doc as it could be that your best is higher than you think, you've just been under treated so haven't managed it (I've hit a new 'bests' on 3 different occasions, usually after intense treatment in hospitals).

    PF is just there to give an indication for management, but you know your body and when you need more/less than the reading suggests do what feels right.

    Hope that clear up the difference in PF not correlating with symptoms!

  • Thank you for your reply EmmaF91. This is very helpfulx

  • An older post in a different message thread explained this as being due to PF measuring the performance of the larger airways, rather than the smaller alveoli which can be behaving differently. Main thing is that any medication is making you feel better; it's all about how you feel rather than a numbers game!

  • There might be other factors the contributing to PF, since you have an scheduled appointment so a consultant will guide you best

  • Very important as others have said, to do this at the same time of day. Also ensure your technique is the same (you should be standing, too). My asthma can be good and my allergies bad so I only check mine if I don't 'feel right' as then the reading might indicate I need to up my preventer. Otherwise I don't regularly do Peak Flow unless Dr has asked me to do so for checking purposes.

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