Fev1

[Denae011]

Hi i got a letter off my consultant today and it says fev1\fvc 1.35/2.55. Recent best 2.2/2.5 ( 2008 ). What does this mean? I don't know the readings of spiromatory test. Is this similar to peak flow?

[Superzob]

You should be able to breathe out most of your lung volume (FVC) in about one second (FEV1), which you were doing in 2008, but that ability reduces with age and possible asthma/obstruction. Your consultant will no doubt be advising you of the best course of action, but don't worry as there are plenty on this forum with much worse results (including me!) and hardly notice; there's a lot of spare capacity in your lungs!

[Denae011 in reply to Superzob]

Ah thank u for reply. I am on a lot of treatment already. He did say when I go no in 6 weeks there maybe another treatment he can add.

[vissidarte]

Is this similar to peak flow? - Not exactly. Peak flow and FEV1/FVC both measure lung function, but do it in different ways.

Peak flow is the maximal flow of the air flowing out of your lungs. The longer you exhale, the slower the flow gets until it stops entirely. It is an easy way to measure at home how hard you are working to breath, but it is only one of many ways.

FEV1 in FEV1/FVC is the amount of air you can exhale in one second. Its an average of the peak flow and all the smaller flows during the first one second of exhalation. It is both a volume and a flow. It is a volume because it is an amount of air. It is a flow because it is volume per 1 second.

FVC in FEV1/FVC is the total amount of air you can exhale. It is only a part of your total lung volume. Your lungs always keep a little bit of air inside them - this is called "reserve volume" or RV for short. Thus your total overall volume is FVC + RV.

FEV1/FVC is the percentage of your total exhale volume that is expelled during the first 1 second of a forced exhalation. If it is lower than expected it means there is obstruction in your lungs.

In asthmatics FEV1 and FEV1/FVC can change a lot. You will get numbers like your best when you are well. When you are unwell, the numbers will usually be lower. When the asthma exacerbation ends, the numbers usually return to your best.

Normally FEV1/FVC is between 80-90%. Your healthy best is 88% (2.2/2.5). But your last test was lower 53% (1.35/2.55). This drop usually means that you are having an asthma exacerbation - but I suspect you already knew that from the way you feel. Another marker of an asthma exacerbation is FEV1 < 80% of your best - your most recent FEV1 was about 60% of your best - again a sign that you aren't breathing as well as you do when you are feeling better.

If you are having frequent exacerbations on your current medication , this may be why your consultant is considering changes in your asthma medications.

[Denae011 in reply to vissidarte]

Thank you very much for your reply. I understand now. When I asked my doctor they just said it was nothing to worry about. And you are right my asthma is quite bad at the minute.