Diagnosing Idiopathic Pulmonary Fibrosis

Reviewed by Neha Pathak, MD on December 07, 2020

Shortness of breath is one of the telltale signs of idiopathic pulmonary fibrosis, but it's also a symptom of lots of other conditions. Your doctor may suggest several tests that can help confirm a diagnosis of IPF, which is brought on by scarring in your lungs.

Get Yourself Checked Out

If you or your doctor think you may have the disease, make an appointment as soon as possible with a pulmonologist, a specialist in lung health.

They'll ask you about your family history and past medical issues. They'll want to know about things like:

  • Whether you've ever smoked or used drugs
  • What kind of work you do (to see if something you breathe in at your job could irritate your lungs)
  • Other medical problems you have
  • Whether anyone else in your family has lung disease
  • How long you've had symptoms, such as shortness of breath or coughing

They'll also give you a physical exam, which will include listening to your breathing through a stethoscope. If you have IPF, they may hear a crackling sound in your lungs.

Tests for IPF

Your doctor may ask you to get tests that look for damage in your lungs. They can also help rule out other diseases.

Some you can take in your doctor's office without any special preparation, but for others you'll need to go to a lab or hospital.

Chest scans. An X-ray lets your doctor see the structures inside your body. It may show shadows on your lungs that suggest scar tissue.

You may also need an HRCT scan (high-resolution computed tomography). It's a sharper and more detailed type of X-ray that can spot signs of IPF at an earlier stage.

Breathing test. Your doctor may use a device called a spirometer to measure how well your lungs are working.

You take a deep breath in and then blow as hard as you can into a tube connected to the device. You'll wear a clip on your nose so you can only breathe in and out of your mouth.

Pulse oximetry. Your doctor clips a small sensor to the tip of your finger or ear. It sends a painless beam of light through your skin to check the oxygen level in your arteries.


Blood test. It's used to check your oxygen and carbon dioxide levels.

Your doctor takes blood from an artery on the inside of your wrist, arm, or groin. It may be slightly more painful than a regular blood test, which takes a sample from your veins.

You may feel some discomfort. You'll need to sit calmly and keep pressure on the spot for a few minutes afterward to keep it from bleeding.

Skin test. Tuberculosis causes symptoms that are like IPF, so you may need a test to rule out this disease. Your doctor uses a tiny needle to inject a substance under the top layer of skin on your arm. This will form a small bubble, like a blister.

You'll need to see your doctor or lab technician 48 to 72 hours later to see if there's a reaction, which will look like a red, swollen bump.

Exercise test. It measures how well your lungs push oxygen through your bloodstream while you're moving around. You may have to walk on a treadmill or pedal a stationary bike while hooked up to devices that measure your heart rate, blood pressure, and how much oxygen is in your blood.


Lung biopsy. The best way for your doctor to diagnose IPF is to take small samples of tissue from your lungs and check them under a microscope for signs of scarring or other disease.

There are different ways to do it. Your doctor may put a needle through your chest, or they may put a long, thin tube through your mouth and down your throat.

For some biopsies, you'll only need "local anesthesia," which is medicine that numbs an area on your body. For others you'll need drugs that make you sleep while the procedure is done.

You may be asked to stop eating for 8 hours before the biopsy. Make sure to find out if there are any other ways you need to prepare.

Other lung tests. You might need to go to a hospital to get other exams done. For example, you could get a video-assisted thoracoscopy or bronchoscopy. Your doctor puts a tiny tube with a camera on the end through a cut in your chest or into your nose or mouth.


For a test called a bronchoalveolar lavage, your doctor injects salt water into your lungs to help collect tissue samples.

Another option is a thoracotomy. Your doctor removes small pieces of lung tissue through a cut between your ribs.

You'll get medicine that puts you to sleep during these tests. Talk to your doctor about how you should prepare and what you should expect afterward.

WebMD Medical Reference



National Heart, Lung, and Blood Institute.

Coalition for Pulmonary Fibrosis: "Facts About Idiopathic Pulmonary Fibrosis."

Johns Hopkins Medicine Health Library.

Lab Tests Online (American Association for Clinical Chemistry).

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