Every bulletin I read people saying they are grade 4 COPD or their breathing (fev1?) has gone down from 60% to 52% or whatever. But I have had tests across the last three years that range from 45% to as low as 32%. And I know that there are days when I really do feel 30% and others when I am twice as good. I am very puzzled. Is it really possible to take these tests and get useful information from them that is accurate from person to person or are they, as I think, far too variable to really help. And if that is the case should sufferers worry so much that it affects their mood and temper?