When does your personal best peak flow change?

[Mandevilla]

How long do you go without achieving your personal best peak flow before you downgrade it to a new 'best'?

[Lysistrata Administrator Community Ambassador]

I think it's 6-12 months -this post may help if you haven't seen it, though you may already know some/most of this: healthunlocked.com/asthmauk...

From the post: Best scores can also increase and decrease over time (age being a factor 😉), so I think they say your best only counts if you’ve hit it in the last 6 months (I get confused between 6 or 12 but think it’s 6 😅), and you should hit it multiple times to confirm its your best (can be done all on the same day 😉). Those new to asthma often find as they gain control (and practice PF technique) their best also increases... personally I think it took a year before I found my best, and had to change my plan about 6 times 😅. And yes to anyone questioning, when you get a new best, you should then adapt the numbers of when you should seek help!

If you've been poorly controlled and up and down for a while, you're probably not going to have been hitting your best, especially if you tend to test only when you get symptoms. I try to make a point of doing it every so often on a really good day, and/or post meds, to see if I can still hit my best. I can still hit it now, even if not all the time - this week I've been madly stressed about my clinic appointment so it's been wonderful all week because my lungs love stress, it's like an anti-trigger for me! (Shame about the rest of my body lol).

It does count post-meds btw, though some medical people will try to tell you it's 'cheating' post meds and doesn't count. However, a major part of asthma is determined by how much difference reliever meds make to your peak flow, which to me means a post-meds number can definitely count as a best. You do need to hit it more than once though.

[Mandevilla in reply to Lysistrata]

Thanks, that's really helpful. I guess allowing at least 6 months makes sense as it allows for seasonal fluctuations. I do check it regularly as I'm still working out what makes me better/worse and monitoring peak flow is quite helpful in doing that.