Sometimes spirometry is done in conjunction with other PFTs.
Purpose of Test
Spirometry measures key aspects of pulmonary (lung) function.
Spirometry is rarely used alone to diagnose a lung condition.
Illustration by Emily Roberts, Verywell
This can help determine if a treatment is working or needs to be modified.
You may also experience coughing.
These symptoms are normal and rarely a cause for concern.
People with asthma are at a small risk of an asthma attack during spirometry.
In such instances, the exertion can cause temporary, sudden, and severe breathing problems.
Timing
A spirometry test typically takes around 45 minutes.
It can take longer depending on waiting times.
Ask your healthcare provider if the test may take longer so that you' can plan ahead.
In most cases, spirometry is performed by a pulmonary function technician or a respiratory therapist.
At-home spirometry testing machines are available for healthcare provider-supervised monitoring of a lung condition.
Don’t wear a belt or clothing that fits tightly around your chest or waist.
Food, Drink, and Medications
Little preparation is required before having a spirometry test.
You also may be responsible for a co-pay or coinsurance.
Prior authorization may be needed.
Speak with your healthcare provider in advance to better gauge your expectations.
Pre-Test
After you arrive for your appointment, you will check in.
When you are called for your test, you will be asked to empty your bladder.
You will then be escorted to the room where PFTs are performed.
The technician or respiratory therapist will typically record your height since this will influence how the tests are interpreted.
If you wear dentures, you will leave them in for the test.
Most likely you’ll be given a tube-like mouthpiece to breathe into.
Less commonly, there are portable devices about the size of a camera with a mouthpiece and digital read-out.
The spirometer will create a graph that records the speed and amount of air as you breathe.
To be considered accurate, the tests must be reproducible (meaning the same results are achieved repeatedly).
So you’ll be asked to repeat the test a minimum of three times.
If you feel dizzy or lightheaded, or can’t stop coughing, let the technician know.
In most cases, all you will need is a short break to recover.
An obstructive pattern is seen in lung conditions such as COPD and asthma.
Restrictive diseases are most often the result of a condition causing stiffness in the lungs.
There is extra-thoracic restriction and intra-thoracic restriction.
This includes obesity,scoliosis(abnormal curvature of the spine), diaphragmatic paralysis, and pleural effusion.
Intra-thoracic restriction includes diseases of the lung parenchyma, including fibrosis.
Sarcoidosis (an inflammatory disease that causes abnormal growths in tissue) causes mixed airway obstruction and restriction.
Some patients require bronchoprovocation to make the diagnosis of asthma.
This includes a test called a methacholine challenge.
On the downside, the accuracy of home spirometry units can vary by brand.
Cheaper ones tend to be less accurate, while recommended ones can often be unaffordable.
Your healthcare provider can recommend the unit best suited to your condition.
Home spirometers are sometimes covered by insurance, at least in part, if medically indicated.
It’s a rig designed to help keep the lungs clear after surgery.
And changes to your test results over time may help guide your treatment.
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