Role of Pulmonary Function Tests in Pulmonary Diseases

Role of Pulmonary Function Tests in Pulmonary Diseases

Pulmonary function disease or pulmonary disease is a general umbrella term that points to disorders related to the lungs and the other parts of the respiratory system. These are some of the most common medical conditions in the world. The lungs are a big and complex system and pulmonary function disease can be seen in any part of this system.

A pulmonary function disease can be obstructive, meaning the air has trouble flowing out of the lungs due to a resistance in the airway, or it may be restrictive, meaning lung tissue or chest muscles cannot expand enough and this creates airflow problems due to lower lung volumes.

Types of pulmonary function diseases

These diseases can be split into 6 categories based on the part of lungs they are affecting:

  1. the airways (asthma, COPD, cystic fibrosis etc.)
  2. the alveoli - air sacs (pneumonia, tuberculosis, emphysema etc.)
  3. the interstitium - the thin lining between the alveoli (sarcoidosis, idiopathic pulmonary fibrosis etc.)
  4. the blood vessels (pulmonary embolism, pulmonary hypertension)
  5. the pleura - the thin lining surrounding the lungs and lining the inside of the chest wall (pleural effusion, pneumothorax, mesothelioma)
  6. the chest wall (obesity hypoventilation syndrome, neuromuscular disorders)

What is the role of pulmonary function tests in these diseases?

Pulmonary function tests (PFTs) are used to see how well the lungs are working. They are noninvasive and measure certain values such as lung volume, capacity, flow rates etc. This information can be used to detect the general type and severity of the pulmonary disease. They cannot define a specific cause of the problems but can be used to diagnose some disorders such as asthma and COPD.

Different pulmonary function test types

PFTs have several different types. These are:

  1. Cardiopulmonary exercise test: gauges the patient’s ability to exercise and diagnoses what may be restricting their activity levels. It is usually performed on some sort of exercise device such as a treadmill and lasts about 10 to 12 minutes.
  2. Bronchial provocation test: evaluates the sensitivity of the lungs and is often used to diagnose if asthma is the reason for the symptoms.
  3. Exhaled nitric oxide test: measures the amount of nitric oxide in your breath. An elevated level of this points to the potential of inflammation in the lungs and allergic asthma.
  4. Pulse oximetry test: measures the saturation of oxygen in red blood cells.
  5. Plethysmography test: measures lung volume.
  6. Diffusion capacity test: measures how well the alveoli work.
  7. Spirometry: it is one of the most common pulmonary function tests. It measures the amount of air that can be exhaled and inhaled in one forced breath and is conducted with spirometers.

Pulmonary Function Disease

When a patient has a pulmonary function disease, it is very important for their lung capacity to be constantly monitored. The easiest way of doing this routinely is through spirometry tests, but constantly going to the hospital or a physician’s office may not always be possible. This is why personal spirometers are very important for day to day lives of patients with respiratory diseases. With SpiroHome Personal spirometers, patients can get professional care in the palm of their hands and are able to be constantly monitored by their healthcare team using SpiroCloud. Follow the link to request a demo!


  1. "Lung Diseases Overview", Matthew Hoffman, MD, 2020.
  2. "Pulmonary Function Tests", John Hopkins Medicine.
  3. "Pulmonary Function Testing (PFT)", Rebecca Dezube, MD, 2021.
  4. "All About Pulmonary Function Tests", Healthline, 2021.

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