Pulmonary Function Tests to Evaluate Lung Disorders

What Do PFTs Measure?

Lung function tests provide valuable information by recording a wide range of specific measurements, including:

• Tidal volume: Amount of air breathed in or out during normal breathing.
• Minute volume: Total amount of air breathed out per minute.
• Vital capacity: Total volume of air that can be breathed out after breathing in as much as you can.
• Functional residual capacity: Amount of air left in lungs after breathing out normally.
• Residual volume: Amount of air left in the lungs after breathing out as much as you can.
• Total lung capacity: Total lung volume when filled with as much air as possible.
• Forced vital capacity (FVC): Amount of air breathed out forcefully and quickly after breathing in as much as you can.
• Forced expiratory volume: Amount of air breathed out during the first, second and third seconds of the FVC test.
• Forced expiratory flow: Average rate of flow during middle half of the FVC test.
• Peak expiratory flow rate: Fastest rate you can force air out of your lungs.

PFTs Can Help Diagnose a Variety of Lung Conditions

Pulmonary function tests are commonly used to help diagnose and/or assess the effectiveness of current treatments for chronic respiratory conditions, such as:

• Allergy-mediated lung diseases
• Asbestosis (lung disease from inhaling asbestos fibers)
• Asthma
• Bronchiectasis
• Bronchitis
• Chronic obstructive pulmonary disease (COPD)
• Cystic fibrosis
• Emphysema
• Respiratory infections
• Restricted airway from scoliosis, inflammation, or scarring
• Interstitial lung diseases (group of diseases that cause scarring of the lungs)

In addition, PFTs are routinely performed in certain work environments, such as graphite factories and coal mines, to ensure employee health. They may also be used when someone has trouble breathing following a chest injury or surgery. For individuals with lung or heart problems, smokers, or those with other health conditions, PFTs may be used to check lung function before surgery or other procedures.

Types of Pulmonary Function Tests

There are several types of PFTs. Your doctor may order one or more of these tests depending on your symptoms and health conditions. Recommended tests may include:

What Happens after a Pulmonary Function Test?

If you have a history of lung or breathing problems, you may be tired after the test. You will be given a chance to rest afterwards.

A pulmonologist will review your test results and compare them the average readings for someone of the same age, height, sex and race. Results are also compared with any of your past test results. The doctor will share their findings and recommendations, usually within 48 hours.

If any of your lung test results are abnormal or have changed over time, additional testing may be required.

Potential Risks of Pulmonary Function Tests

Because pulmonary function testing is not an invasive procedure, it is usually safe and quick for most people. Some individuals may experience dizziness, shortness of breath, coughing, or an asthma attack brought on by deep inhalation during the tests. Notify your respiratory technologist if you feel lightheaded or have other symptoms.

PFTs may not be recommended if you have/had:

• Recent eye surgery
• Recent abdominal or chest surgery
• Recent heart attack
• An unstable heart condition
• A bulging blood vessel (aneurysm) in the chest, abdomen, or brain
• Active tuberculosis or respiratory infection

Pulmonary Function Test Locations

The respiratory health experts at University Hospitals offer pulmonary function tests at multiple locations across the region for easy patient access.