Pulmonary function tests (PFTs) are lung tests. It is performed to ensure the proper functioning and condition of your lungs. This is a non-invasive and painless test, which means it does not require cutting your skin or putting any tool inside your body.

This group of tests helps detect and identify many lung-related issues and disorders. These tests help measure the conditioning of the lungs by providing information about their volume, capacity, air exchange, and rate of gas flow from lung to blood and vice versa.

The reports of these PFT tests help your doctor to create a treatment plan for various health-related disorders and diseases. Usually, PFT tests are also performed before surgery to check the condition of the lungs of a patient who is a regular smoker or who has heart-related problems.

PFT tests are done to diagnose the following diseases:

• Lung diffusion capacity- this test is a bit similar to spirometry which help diagnose a disease blood vessel between patient’s heart and lungs, it shows the damage done by a disease called emphysema.

• Asthma
• Allergies
• Chronic obstructive pulmonary disease (COPD)
• Damaged lung tissue
• Chronic bronchitis
• Infection
• Lung cancer
• Sarcoidosis
• Thickened, stretched, or enlarged airways

There are various types of test involved in PFT tests, which are discussed below briefly:

• Spirometry - This is one of the most common PFT tests, which help diagnose breathing problems such as asthma. in this test, you’ll quickly breath in as much air as you can and release out as much as you can through a tube connected to a device called a spirometer. It measures the volume of air you can breathe in and breath out in a single go.


• Body plethysmography - in this test you take a deep breath and measure the amount of air in your lung when your intake and also check the amount of air remain in your lung after you exhale air as much as you can. It confirms whether you have lung disease which reduces the space in your lungs.


• Lung diffusion capacity - this test is a bit similar to spirometry which helps diagnose a disease blood vessel between a patient’s heart and lungs, it shows the damage done by a disease called emphysema.


• Bronchial provocation test - this test is done to confirms the asthma and how much damage it has already done and how severe it is. You inhale a medication that will make your airways narrow then you go through spirometry test and its reading will help to conclude how much your airways narrow during an asthma attack.


• Cardiopulmonary exercise stress test - in this test, you run on a treadmill or ride a stationary bicycle to keep a track of your heart rate. Your breath out in a tube to monitoring the function of your lungs during physical exercise. This test is usually performed on a patient having heart diseases or lung diseases.


• Pulse oximetry test - during this test, a probe to your finger, earlobe and other part of your skin is used to detect the oxygen presence in your red blood cell. This is a complete painless procedure.


• Arterial blood gas test- this test requires your blood to check the level of gases like oxygen and carbon di oxide in blood which is taken from one of your arteries.


• Fractional exhaled nitric oxide test - in the case of asthma, patient might have high level of nitric oxide gas in their body. This test is performing to determine the amount of the nitric oxide when you exhale air.