Spirometry plays a key role in both diagnosing and monitoring lung conditions. However, the results can be a bit confusing if you don’t know what to look for. Make sure you understand the numbers on your spirometry test and what they mean for your overall lung health.
How to Read the Results of Your Spirometry Exam
The purpose of a spirometer is to measure the total capacity of your lungs. It reflects the results using several different tests, so make sure you understand the difference between each test. Generally speaking, you will receive numerical values for each of the following.
FVC
Your “FVC” score refers to your forced vital capacity, which is how much air you can exhale during an extended breath. It simply reflects the volume of air you can forcibly blow out after full inspiration.
FEV1
Likewise, your “FEV1” score refers to your forced expiratory volume in one second. It simply describes the volume of air you can exhale in a one-second period. Like the FVC score, your FEV1 means little by itself. After all, your total lung capacity is only a number until it is compared to what is universally “normal.”
FEV1%
Your FEV1% (or your FEV1/FVC ratio) takes the results of the above tests and assigns you a percentage. This percentage reflects where your total lung capacity falls compared to those of your same sex, age, weight, etc. In other words, it averages the results of everyone and then tells you whether your lung capacity is above average or below average.
What Do the Numbers Mean?
Generally speaking, a healthy FEV1% for adults is above 70%, while a healthy FEV1% for children is 80-85%.
Keep in mind that although your spirometry scores might reflect where you fall in comparison to others, it mostly exists to help you monitor your own “normal.” If your normal FEV1% is around 75% and then suddenly dips to 70%, it indicates that you have been exposed to an asthma trigger or perhaps have a respiratory infection. Spirometry exists to help you monitor your lung condition, better equipping you to maintain and control it.
How Does Spirometry Help You Monitor Your Asthma?
Doctors use spirometry to help diagnose asthma in patients, but it serves other purposes as well. When properly utilized, an at-home spirometer allows you to monitor both improvements and declines in your overall lung health. Tracking test results allows you to notice patterns in symptoms, triggers, and daily experiences.
It is a good idea to log your spirometry test scores in your asthma attack action plan. This plan uses data from your daily life to formulate responses to emergency situations. Particularly if your child is the one dealing with asthma, it is important to know what medication to use, who to call, what triggers to avoid, etc.
Taking the tests, understanding the numbers, and formulating a plan of action empowers you or your loved one and provides a measure of control over lung health.
