How Is Pulmonary Fibrosis Diagnosed?
Your pulmonologist (lung doctor) will take a thorough medical, social,
family, and work history. This is to try to identify a cause for the disease,
if there is one. Your doctor will do a physical examination and listen to
your lungs with a stethoscope for abnormal breath sounds. Additional
testing may include:
Lung Function Tests
• Pulmonary function testing: This test involves breathing through a tube that
is connected to a machine. It measures the volume of air in the lungs. It also
measures how much and how rapidly air can move in and out of the lungs. If PF
is diagnosed, this test is often repeated a few times a year to see if there is any
change or worsening.
• Pulse oximetry: This test uses a small device that is typically placed on the tip
of a finger. It measures the amount of oxygen (oxygen saturation) in the blood.
You may be asked to walk while oxygen saturation is continuously measured.
This will show if you need supplemental oxygen when exerting yourself if the level
drops below 89%. Many living with PF will order a pulse oximeter for home use to
monitor oxygen saturation.
• 6-minute walk test: This test measures how far you can walk in 6 minutes. It
may be repeated throughout the year with pulmonary function tests if pulmonary
fibrosis is diagnosed.
• Arterial blood gas test: This test measures the levels of oxygen and carbon
dioxide in your bloodstream. It involves blood sampling from an artery in the wrist.
• Overnight oximetry: This test measures your oxygen saturation by monitoring
your blood oxygen levels overnight while you are sleeping. The test shows if you
need supplemental oxygen during sleep. For this test, you wear a monitor on your
finger that records the amount of oxygen in your bloodstream while you sleep.
Imaging Tests
• Chest X-ray: Chest x-rays can show the scarring of the lungs. This test is usually
the first diagnostic test to examine the lungs when there is the suspicion that a
patient may have PF. It is also used on subsequent visits to tell if disease is stable
or getting worse.
• Computerized tomography (CT) scan: CT scanners take many x-rays from
different angles to show cross-sectional, highly detailed images of the lung. A high-
resolution CT scan (HRCT) is often used to diagnose PF because the images are
more precise. This helps determine the extent of lung damage or scarring caused by
PF and shows changes to the lungs in much greater detail. In many cases, a HRCT
is clear enough for your doctor to make a diagnosis (in combination with history and
blood tests) so that a lung biopsy may not be needed.
• Echocardiogram: This is an ultrasound test that uses sound waves to get pictures
of the heart. It allows doctors to measure pressures in the heart chambers and
helps determine if the pressure in your lungs is abnormal as a result of the scarring
of the lungs.
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