working out fev1 as a percentage

[ccccc]

Hi

I've bought an asthma-1 Vitalograph FEV1 to monitor my asthma between appointments as I don't think peak flow really shows my asthma up very well.

When I blow into it it just shows a number eg 3.87 , not a percentage as it doesn't measure FVC and there's no instructions in with it other than a diagram of how to do the test.

I have found the manufacturer's table of 'normal' readings online by age and height. So is it just a matter of working it out as a percentage eg 3.87 as a percentage of 4.28 (which is the 'normal' reading for my age and height)?

thanks

[Troilus]

The only way I know of to get your fvc is on spirometry. I did once try to look it up to find an at home method and it involved balloons and water displacement when you let it out or something similar!

The was I track is I track my peak flow to see I’m in my range and track fev1 separately to see if I am within my range.

If you have recent spirometry results you could use that, but fvc varies like peak flow.

There must be a correlation between peak flow and fvc that someone might know.

[Homely2 Administrator]

Your fvc will not be the same as the normal reading, so you cannot really use the normal reading