How to read a Spirometer – spirometry normal values

spirometry normal values

Spirometry is a routine test performed to determine if you suffer from lung problems such as Chronic Obstructive Pulmonary Disease (COPD) asthma and other ailments. It is a fairly short procedure that lasts about fifteen minutes and can help your doctor determine what might be wrong with you and what is the best course of treatment. All you do is sit down and breathe into a small machine, spirometer. That’s it.

Measurements and Terms

A spirometer measures the speed that lungs change in volume during forced breathing exercises beginning with a full inhalation, you rapidly empty your lungs of air and continue until max exhalation volume. Then these results are charted.

There are some basic terms you will on the chart that your doctor will explain to you, but it is helpful if you already have an idea of what they mean. The test measures four different aspects of lung function: expiratory reserve (exhale), inspiratory (inhale), residual and tidal volume. All of these are combed together to measure your total lung capacity (TLC). Different combinations of measurements have different terms such as functional residual capacity (FRC), inspiratory capacity and so on.

All you have to do is take the measurements and calculate them to determine what’s going on. Fortunately, the CDC has an online calculator, so just plug in the information here and you will be able to see what your results are.

Interpreting the Data


After you receive the calculation, it will be clear to see the health of your lungs. Your results will be within a certain range, based on your age, height, and weight. These factors determine your spirometry normal values. If you are within the range, then your lungs should be free of most major problems. If you are still suffering discomfort, then your doctor may decide to perform other tests to see what else could the problem.

If you are past this range of normal values, then it will be clear that you are suffering from COPD. There are four stages of it depending on where you fall on the scale, which determines the severity of the diagnosis.

How to Improve Your Results

Spirometry is a good indicator of not only your lung but also your general health. Your doctor will advise you of the most common tips for better lung function. Be sure to quit smoking as this is the most effective way to slow the decline of lung function. Also, you need to discuss dietary, exercise and medication regimens to help improve overall respiratory capacity and efficiency.

A Very Effective Test

If you have been suffering from a persistent cough or other lung issues for a period of time, then you should consult your doctor. It is important to ensure you fall within spirometry normal values to confirm what may be causing the problem. From here, you can begin treatment and be on the road to lung health!