Spirometry (Asthma)

5) What is measured

  • FEV1: Forced Expiratory Volume 1 – This is the volume of air that is forced out in 1 second.
  • FVC: Forced Vital Capacity – This is the volume of air that can be forced out of the lung from full inspiration to full expiration.
  • FEV1/FVC: Spirometric ratio – This compares the amount of air that can be forced out of the lungs in the 1st second, with the total amount of air that can be forced out. Using this ratio the healthcare professionals can work out how your asthma is affecting your lungs and the appropriate treatment for you.
  • PEF: Peak Expiratory Flow  – This measures the speed you can breathe out.