6) Technical terms you may hear after spirometry tests

FEV1 or Forced Expiratory Volume 1

  • The maximum volume of air forced out from your lungs in 1 second (from full deep breath in).

FVC orĀ Forced Vital Capacity

  • The FVC is measured by taking your biggest breath in (total lung capacity) and blowing out as fast as possible until you cannot breathe out any more.

Spirometry tests show the amount of air that comes out in the first second (FEV1) as a percentage of the total volume air blown out.(FVC)

The two results together (FEV1 and FVC) are used to calculate the level of your COPD as a percentage of the predicted value for someone of a similar age, height and weight. For example a normal test would be 80% or more predicted value. Very severe COPD could show a predicted value of 30% or less.

Your treatment will depend on the results of your spirometry test and this will be discussed with you by your respiratory team. Results are usually classified in to mild, moderate, severe or very severe depending on the percentage of how well your lungs are working.

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