Can someone help me understanding Peak Flow?
When I use my peak flow meter I blow around 390. But when I was with the asthma nurse yesterday her meter read 470. Mine has a yellow strip, hers is black.
I found this website (http://www.peakflow.com/top_nav/normal_values/PEFNorms.html) which said there are two types of meter, the Wright-McKerrow scale, which is given in black, and the EU scale, which is shown in yellow. According to the website someone of my age and height should blow 492 on the black scale and 447 on the yellow scale.
Is it all in my head and my asthma isn't as bad as I think it is (bad for me that is), or is my asthma nurse using the wrong meter and therefore getting it wrong?
According to my peak flow meter I used to be able to blow around 440, and now I average around 390, and I don't feel like my asthma is under control like it used to be, but the asthma nurse doesn't think there's a problem so I don't know what to do.