Does anyone know if the fev1/Fvc ratio can fluctuate?

[Tinkz]

2 months ago my ratio was 81 and fev1 Fvc normal Limits, this was a month after a course of pred not sure if that would of made the results good, yesterday during a bronchial challage my base fev1/ratio was 75, I'm 30 so very close to the cut off. amazed with the drop in two months?

[Badbessie]

Many things can alter this from a slight chest infection to the time of day. It can jump either way.

[soulsaver]

Hi - yes it can fluctuate, cold morning on a full English breakfast will get you a significantly different result than a warm summer afternoon on empty, for example, and there are other varying influences in my experience. Also you will see a change after the tail off from Preds - they usually avoid spiro within 6 weeks to dodge the influence.

I'm not sure that your age matters that much in this ratio - believe 80% Fev1/FVC means you can blow out 80% of the air in your lungs in 1 second - so is in near the top of the normal range at all adult ages.