Peak flow

[Levans29]

I’m confused about my peak flow readings I’m 29 female and a reading of just over 650 is this good or bad?

[M-A-000]

I am 33 and same readings, my peak flow more than 650, with asthma, I got severe flu and chest infection and it dropped to 550,

[twinkly29]

That reading is pretty high generally but actually peak flow is only relevant relative to one's own best - anyone else's scores are not important.

So if your best is 650, then as long as it's above 520 (80% of your best) then you're totally ok in terms of peak flow itself. So in M-A-000's example, peak flow dropping to about 85% is actually fine in terms of peak flow.

This post explains everything you need to know:

healthunlocked.com/asthmauk...

[runcyclexcski]

What Twinkly says -- take your readings when you feel "great" (or after/on steroids, or after a nebulizer/rescue relief) and have your nurse write you a card which states your "personal best" and the "80%" level. Who knows, may be your PB is 750. Have this card on you at all times. When you feel sick and come to an AE, show them the card, b.c. for the ***average*** female your 650 is quite high (my wife's is 400). W/o the card, it may be difficult to convince them that you need urgent care. My PB PF is 940, and all of my "bad" days (700) are not even on the standard chart table of PF that my respiratory hospital uses as a standard diary form.

[ReedB]

All good advice and yes, 650 is good. My personal best is 520 (late 30's)... I will add though that my peak flow only has to drop a small amount before I need extra meds like steriods. Usually once I hit 470 I know I'm getting into difficulties. I only got down to 400-450 when I was needing an ambulance! I'm one of the odd ones!As others have said you learn what's your best and what works for you.

[Hidden]

There are charts you can access via google as it depends on your age etc. But this sounds good.

[Lysistrata Administrator Community Ambassador]

I agree with twinkly29 - and definitely recommend you read the post by EmmaF91 she linked to. To quote from that:

"Some of the things that can affect your best scores are; gender, height, age, weight, PF technique, standing v sitting, time of day, high level/endurance/frequent sports, playing wind instruments, singing frequently/professionally/in a choir and smoking to name but a few. Factors like sports, music and smoking have a greater effect as a child, so the changes may last into adulthood, however it will affect as an adult too. This is why it’s pointless comparing best PFs as so many factors go into it, and it truly doesn’t represent anything but how big your lung fields are."

I'm going to guess you may have been involved in something like sports/singing/wind playing? My predicted is about 450 (female, 5'8", 36), but actually my PB is 630, probably because I played the oboe for years when I was younger.

Sometimes there's a bit too much reliance on predicted values but they *really are just population averages for a specific group*. I think that's often forgotten, and too often healthcare staff and others view it as a kind of absolute that you can't deviate from, rather than a guide to use until you work out your personal best.

I also support what others have said about learning how *your* peak flow works. Some people's drops neatly in line with how they feel. Mine does not - I've learned that for me it's more about the pattern such as how much variation there is, how well it responds to reliever and how long that response lasts.