Pulmonary Function Test (PFT) Purpose, Procedure and Risks


Pulmonary Function Test (PFT) also referred to as Lung Function Tests, are the tests that measure breathing patterns and identify the functioning of the lungs. These help in determining the amount of air going in and out of the lungs, and finding out if your lungs work efficiently during physical exercises as well. PFTs are non-invasive diagnostic tests to identify different aspects related to lung functioning such as lung volume and capacities, gaseous exchange, and rate of flow of air. 

Dr. Sheetu Singh explains why is there a need of performing PFTs in certain cases, it is because the functioning of the lungs is significantly related to our life. The regulation of air and hence oxygen in our blood is what keeps our life on the go. Different types of pulmonary function tests rule out different conditions, some find out the amount of oxygen absorbed and mixed into the blood, and others find out the effect of exercise on the lungs. The most common test is Spirometry which checks the amount of air inhaled and exhaled. 

Dr. Sheetu Singh is a renowned lung expert and a leading pulmonologist with a great passion for helping people with pulmonological issues. It creates a lot of discomfort in our daily life and hence requires immediate attention. Her enthusiasm for helping patients with chest ailments, helps her reduce suffering and minimalize discomfort. 


Mostly Pulmonary Function Test (PFT) are advise in cases of chronic conditions such as Asthma, emphysema, bronchitis, and bronchiectasis. Sarcoidosis, allergies, breathing difficulties, or scarring of lung tissues are other possibilities for which these are to be perform. 

Types of lung function tests

  1. Spirometry
  2. Gas diffusion study
  3. Lung volumes or body plethysmography
  4. Cardiopulmonary exercise test


The classical and major method for measuring breathing i.e., inhalation and exhalation Spirometry. In this method, a mouthpiece is connect to which a person breathes. The number of inhalations and exhalations can be counted over some time. Numbers vary when a person is standing, so usually, it is calculated while a person is sitting. This method can evaluate a lot of lung diseases depending on how slow or fast a person is breathing. 

Other ways to calculate lung volume include: –

  1. Plethysmography: it is an accurate way to determine the lung volume when a person is asked to sit in an air-tight box that resembles a phone booth. You are asked to breathe in and out through a mouthpiece and changes in air pressure inside the box allow lung volume to be determined and calculated. 
  2. Another method is by giving harmless tracer ger, usually, for one breath, the difference in the amount of air inhaled and exhaled indicates how effectively gas can travel into the blood from the lungs. 


Because of their non-invasive nature, PFTs have minimal risks and is mostly safe, given a person follows the instruction properly. Rare risks of the procedure include: 

  •  Shortness of breath. 
  •  Coughing.
  •  Asthma attack due to deep inhalations. 
  •  Dizziness. 

Dr. Sheetu Singh suggests people with recent histories of chest or heart surgeries must avoid PFTs. Also, people with conditions like an aneurysm must avoid getting these done. Whenever you experience chest pain or problems, a PFT is required to determine which lung disease you have. If you have lung disease, you should immediately see your doctor or Dr Sheetu Singh for the best lung disease treatment.

Dr. Sheetu Singh, a nationally renowned pulmonologist, Director ILD & Pulmonary Rehab Clinic, is an expert in chest-related conditions. She got her training from SMS Medical College, Jaipur followed by a visit to Cleveland Clinic, USA.

Contact Info

Address: Mahavir Jaipuriya Rajasthan Hospital Milap Nagar, JLN Marg, Jaipur

Mobile: (+91)-8696666380

Email-Id: sheetusingh@yahoo.co.in

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