Simon, it doesn't sound like you've got too much to worry about, and I'd certainly think twice about "fudging" the medical.
I'm not an AME, but I guess the examining doc will be interested in how your condition affects you, medication, hospitalistions, time off work/school, what it stops you doing.
I wouldn'yt worry too much about the figures, but if your interested, your UK doc should be following this....
http://www.enterpriseportal2.co.uk/f...s/qrgjan03.pdf
Go there and tell the truth, and chill.
Sorry, dodgy link try
http://www.brit-thoracic.org.uk/asth...-download.html and follow the bts/sign (quick) download.
There's a longer version but even I'm not that sad.