Pulmonary Function Test

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What are Pulmonary function tests (PFTs)?

Pulmonary function tests (PFTs) are a set of tests that evaluate and measure how well the lungs function. This comprises how well you can breathe and how effectively your lungs can transport oxygen to the rest of your body.

Doctors at Yashoda Hospital & Research Centre, Nehru Nagar, Ghaziabad, are always committed to providing you with the best support and care. They always believe in sharing essential information about various medical concerns. This article will help you to know more about Pulmonary function tests, their uses, and procedure.

When does the doctor recommend Pulmonary function tests?

    • The doctor may recommend these tests in the case:
    • You are having any symptoms of lung problems.
    • You are regularly exposed to certain substances in the environment or at your workplace.

The doctor wants to check the course of a chronic lung disease, such as asthma or chronic obstructive pulmonary disease (COPD).

  • The doctor wants to evaluate how well your lungs are functioning before you have surgery.


Pulmonary function tests are also known as lung function tests.

Why are these tests performed?

These tests are done to examine how well your lungs are functioning. The doctor may ask you to have these tests if you already have a condition that is affecting your lungs to examine if the condition is worsening or how it is responding to the treatment.

Pulmonary function tests may help in diagnosing:

  • Allergies.
  • Asthma.
  • Chronic bronchitis.
  • Respiratory infections.
  • Bronchiectasis, which is a condition in which the airways in the lungs stretch and widen.
  • Lung fibrosis.
  • COPD, which was also known by the name emphysema.
  • Scleroderma is a disease that affects connective tissue.
  • Weaknesses of the chest wall muscles.
  • Asbestosis is a condition that gets caused if you are exposed to asbestos.
  • Sarcoidosis is an inflammation of the lungs, liver, skin, eyes, lymph nodes, or other tissues.
  • Pulmonary Tumor.
  • Lung cancer.

What are the preparations required for Pulmonary function tests?

Before the test, the doctor may ask you to stop taking any medications that open the airways, for example, medicines used for asthma or chronic bronchitis. You must inform the doctor if you are taking any medications so that the doctor may design the tests accordingly. The results of the tests may also get affected if you are taking any pain medications. Do inform the doctor about any of these medications that you are prescribed to take.

You must avoid eating a large meal before the tests. Lungs may not inhale fully if the stomach is full. Before the test, you must avoid tea, food, and drinks that have caffeine. Caffeine causes the airways to open more and this may affect the result of the test. You must avoid smoking as well as any strenuous exercise before the test.

You should wear loose-fitting clothes so that your breathing does not get restricted. You must avoid wearing jewellery as it may affect your breathing. In case you wear dentures, you may wear them to the test to ensure your mouth can fit tightly around the mouthpiece used for the test.

The doctor may delay the tests in case you had a recent eye, chest, or abdominal surgery or a recent heart attack until you have fully recovered.

What are the procedures for the tests?

Spirometry – Pulmonary function tests may include spirometry. The amount of air you breathe in and out is measured by spirometry. The doctor will ask you to sit in front of a machine and you will be fitted with a mouthpiece. The mouthpiece should be fitted snugly allowing the air you breathe to travel into the machine. You may be asked to wear a nose clip to prevent you from breathing air out through the nose. The doctor will assist you throughout the process.

The doctor will ask you to breathe in and out deeply or quickly for many seconds. You may also be asked to breathe in a medication that opens the airways. You may then be asked to breathe again to examine if the medication affected lung function.

Plethysmography test- The volume of gas in the lungs, known as lung volume, is measured by a plethysmography test. The doctor will ask you to sit or stand in a booth and breathe into a mouthpiece. The doctor can determine the lung volume by measuring the pressure in the booth.

Diffusion capacity test- How well the small air sacs inside the lungs, known as alveoli, function is assessed by diffusion capacity test. The doctor may ask you to breathe in certain gases, such as oxygen, helium, or carbon dioxide.

A “tracer gas” may also be used in which the doctor may ask you to breathe once. The machine detects when you breathe out this gas allowing the doctor to examine how well the lungs are able to send oxygen and carbon dioxide to and from your bloodstream.

When may the Pulmonary function tests cause problems?

Pulmonary function tests may cause problems in the case:

  • You had a recent- heart attack, eye surgery, chest surgery, and abdominal surgery.
  • You have a severe respiratory infection.
  • You have unstable heart disease.

Pulmonary function tests are generally safe for most people. However, you may feel dizzy and there is also a risk that you may faint because you may have to breathe in and out quickly during the test. Asthma attacks may be caused to people who are prone to it. In very rare cases, Pulmonary function tests may even cause a collapsed lung.

Looking for specialists or doctors for Pulmonary function tests in Delhi NCR?

The Centre for Chest & Respiratory Diseases at Yashoda Hospital & Research Centre, Nehru Nagar, Ghaziabad has a team of doctors who are highly skilled and well-experienced. They always ensure to provide the best care and support you may need throughout the treatment.

Dr. Brijesh Prajapat has an experience of more than 8 years and has worked with various organizations, such as PGIMS, Rohtak. He is working as Senior Consultant, Pulmonary & Critical Care Medicine at Yashoda Hospital & Research Centre.

Dr. Neerav Tyagi has an experience of more than 29 years and is a specialist of lung & chest( Pulmonologist) at Yashoda Hospital & Research Centre, Nehru Nagar, Ghaziabad. He is highly skilled and has great experience in dealing with tuberculosis, asthma, bronchiectasis, and pneumonia. He has pursued his M.B.B.S. as a gold medalist from King George’s Medical College and M.D. from King George’s Medical University, Lucknow. Dr. Neerav Tyagi is the first in Ghaziabad to start bronchoscopy.

Book an appointment now at Yashoda Hospital and consult these doctors. Visit our official website- Yashoda Hospital. 

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Yashoda Hospital

Yashoda Hospital is one of the best super specialty hospitals in Ghaziabad, Noida & Delhi NCR. Yashoda Hospital aims at providing the best healthcare services across the country and not just in Delhi NCR, Ghaziabad & Noida. Being a super speciality hospital, Yashoda Hospital has a number of dedicated specialities under one roof- gastroenterology, general surgery, obstetrics & gynaecology, cardiology, pulmonology & internal medicine, orthopedics, urology and many more.

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