What you need to know about lung diagnostic tests

Lung diagnostics tests, or lung function tests, serve the purpose of checking if your lungs are working as it should be. Generally, a diagnostic test will measure your lung’s capacity to hold/move air and to absorb oxygen.

These tests are helpful in identifying general lung disorders and determine the severity of the lung disorder. There are different types of lung diagnostic tests namely simple tests, advanced tests, imaging tests and invasive tests.

Type of diagnostic tests

Types of simple lung diagnostic tests are:

  • Spirometry
    The most common lung test, doctors measure how much air goes in and out of your lungs by breathing in and out as hard as you can through a tube.

    A spirometry can diagnose conditions such as chronic obstructive pulmonary disease (COPD).
  • Challenge test
    Upon completion of your spirometry, you are required to breath in methacholine, which irritates your airways causing it to narrow.

    Another spirometry is performed to gauge how the methacholine affects your breathing. This test can be used to rule out asthma.
  • FeNO test
    In a FeNO test you are required to blow slowly and steadily into a device.

    This test is carried out to test certain types of asthma, identify if there is an inflammation in the lungs or how effective steroids are in controlling inflammation.
  • Peak flow measurement
    A small plastic device is used to measure how much air is blown out of your lungs.

    Comparing results with your best reading, this type of test can serve as an advanced warning of an asthma attack.
  • Pulse oximetry
    This device is used to measure just how much oxygen your red blood cells are carrying.

    Usually attached to your fingertips, if your numbers dip below 90%, your healthcare service provider may give you oxygen to help with breathing.

For more severe breathing problems, advanced testing may include:

  • Plethysmography
    This advanced test will give your doctor a more exact measurement of how much air your lungs can hold.

    A plethysmography happens when you are required to sit in a booth, be given a clip to block your nose, while you breathe through a mouthpiece.

    Used to identify ongoing breathing problems such as asthma or COPD, a plethysmography can help doctors determine the next course of action either through medication or surgery.
  • Diffusion capacity test
    This form of test determines just how well your lungs work to pass oxygen into your blood.

    A blood sample may be required to help calculate better results. A diffusion capacity test helps identify damaged lungs or problems with your blood flow.

Other forms of testing may include imaging tests such as:

  • Chest x-ray
    Used to identify pneumonia, an infection may cause fluid to accumulate in the lungs.

    An x-ray may be used to help diagnose cancer or pulmonary fibrosis.
  • CT or PET scans
    A more advanced imaging test, a CT scan is a series of X-rays taken to create a complete picture, while a PET scan uses a special dye to help doctors see parts of the body more clearly.

    A PET-CT scan can be used to identify cancer.
  • Chest ultrasound
    A chest ultrasound, as the name suggests, uses sound waves to capture an image of your lungs.

    This form of diagnostic is done to identify fluid buildup in or around your lungs.
  • Pulmonary angiogram
    A small tube, equipped with a camera, is inserted into your airways.

    Doctors will use it to identify things normally found in your airways such as mucous, blood or tumours.

If I choose to undergo a lung diagnosis, how do I prepare for one?

There are several steps that you can take to prepare yourself for a diagnostic, and help ensure that your breathing is normal and unrestricted.

Steps that you can take are:

  • By avoiding heavy meals before a test
  • Avoiding food or drinks with caffeine
  • Avoid smoking or heavy exercise six hours before your test
  • Wear lose, comfortable clothing

It is always best to get inputs from your healthcare service provider when you choose to undergo your lung diagnostics. Regency’s Heart & Lung Centre is well equipped with specialists and healthcare professionals to diagnose and treat your lung condition.

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