When To Do A Pulmonary Function Test & What Does It Reveal?

Pulmonary function test also called as lung function tests are set of tests that help to determine the health of your lungs. These types of tests help to know how well the lung is able to inhale and exhale air and transfer oxygen present in inhaled air into blood.

Pulmonary function test is a non invasive and painless. It rarely produces any side effects. PFT helps the doctor to diagnose and decide the treatment of lung diseases such as asthma, chronic obstructive lung disease etc. Doctors also recommend this test to know the condition of lungs before major surgery.

Types Of Pulmonary Function Test

Pulmonary function tests (PFT) are two types of tests. One is breathing test and other is to measure oxygen level in the blood. Breathing tests are called spirometry test, plethysmography, and lung diffusion capacity test. Spirometry test helps to know how well the patient is able to breathe in and out. It also measures the amount of air patient is able to blow out.

Plethysmography helps to detect how much air a person is able to take in during inspiration and the amount of air left in the lungs after a person breathes out.

Lung diffusion test measures the amount of oxygen that is saturated in the blood from the lungs. Pulse oxymetry test measures oxygen level in the blood.

When Is A Pulmonary Function Test Required?

Pulmonary function test may be required for many different reasons. It may be done in a healthy person as a part of routine physical checkup. The health care provider may also recommend this test to diagnose a lung condition and assess the extent of lung damage it has caused to the lungs.

Lung function test also helps to know the response of medicine to a lung disease. PFT is valuable test done in lung problems such as:

  • Asthma
  • Allergies
  • Lung cancer
  • COPD (chronic obstructive pulmonary disease).
  • Respiratory infections such as bacterial pneumonia.
  • Problem in breathing caused due to trauma to chest wall or after chest surgery.
  • For diagnosing asbestosis, a lung ailment caused due to constant exposure to asbestos.
  • Sarcoidosis, an inflammatory disease affecting many organs such as liver, eyes, skin, lymph nodes including lungs.
  • Scleroderma, a disease condition in which the connective tissue tends to become thick and hard.
  • PFT is also beneficial to determine the damage caused to the lungs in smokers.

What Does A Pulmonary Function Test Reveal?

Pulmonary function tests are comprised of several tests. Each test has its own significance and reveals the performance of lung function in certain ailments.

  • Spirometry test can show if there is a blockage in the airways. This may reveal to be a sign of asthma, COPD or any other type of obstruction in the lung. It also reveals restricted of air movement which could be a sign of heart failure or fibrosis of lung.
  • Plethysmography is a test that measures the volume of air lung can store when a person breathes in and out. It is beneficial to diagnose and determine damage to the lungs in conditions such as fibrosis of lungs, weakness in chest wall, problems occurring in muscles of chest etc.
  • Lung diffusion tests can reveal problems that can hamper transfer of oxygen from lungs into the blood stream. It is useful test in conditions such as emphysema and problems associated with pulmonary arteries.