Lung Function Tests

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Lung Function Tests

Owing to a variety of lifestyle and environmental factors, lung disorders such as asthma and bronchitis are very prevalent today, with estimates suggesting that approximately 30 million individuals in India are affected by asthma. According to WHO estimates, 13 of the world’s 20 most polluted cities are in India, leading to asthma, bronchitis, heart disease, stroke and a clutch of other diseases.

Lung Function Tests (LFTs), also known as Pulmonary Function Tests (PFTs) are a broad range of tests that determine the health, working capacity and efficiency of your lungs. LFT helps-

  • To measure how well your lungs take in and exhale the air; and how efficiently they transfer oxygen into the blood.
  • To diagnose various lung diseases such as asthma, emphysema, bronchitis


Breathing tests comprise of a major part of Lung Function test, helping doctors measure the oxygen levels in your blood, in order to assess the functioning of the lungs.


These Breathing tests generally constitute of the following tests:

  • Spirometry: helps measure the amount of air you are able to breathe in and quickly exhale
  • Lung Diffusion Capacity: helps determine how efficiently oxygen is passed by your lungs to your bloodstream.


Lung Function tests are generally performed in order to measure the following parameters:


  • Tidal Volume (VT) – the total volume of air inhaled and exhaled during normal breathing
  • Vital Capacity (VC) – the total volume of air you can exhale after inhaling to your lungs’ maximum capacity
  • Minute Volume (MV) –  the total volume of air exhaled per minute
  • Functional Residual Capacity (FRC) –  the total volume of air left in the lungs after exhaling normally
  • Residual Volume – the total volume of air left in the lungs after exhaling as much as you can
  • Total Lung Capacity – the total volume of the lungs when filled with as much air as possible
  • Forced Vital Capacity (FVC) – the total volume of air exhaled forcefully and quickly after inhaling as much as you can
  • Forced Expiratory Flow (FEF) – the average rate of flow during the middle half of the FVC test
  • Forced Expiratory Volume (FEV) – the total volume of air exhaled during the first, second and third seconds of the FVC test
  • Peak Expiratory Flow Rate (PEFR) –the fastest rate that you can force air out of your lungs


The normal values of the lung capacity test vary from individual to individual. The results of your tests will be compared with that of the people who share the same age, height, sex and race as you.


At Apollo Clinic, we use cutting-edge Pulmonary Lung Function Test equipment, follow strict protocols and have a team of highly skilled and experienced doctors and support staff in order to ensure the proper diagnosis and results.

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