Pulmonary Function Tests

Pulmonary function tests (PFTs) are noninvasive tests that measure lung capacity, volume, gas exchange and rates of flow. Doctors use them to diagnose and select a treatment for certain lung disorders.

What are pulmonary function tests?

Pulmonary function tests (PFTs) are noninvasive tests that measure lung capacity, volume, gas exchange and rates of flow. Doctors use them to diagnose and select a treatment for certain lung disorders. The two disorders that cause lung issues are restrictive and obstructive.

Restrictive disorders occur when the lung tissue and/or chest muscles are unable to fully expand. This will create issues with air flow. Obstructive disorders occur when air cannot flow out of the lungs properly due to airway resistance. This also results in decreased air flow.

Normal values for pulmonary function tests vary from person to person. Your test results will be compared with the average data from someone of your same age, sex, race and height. If you have had a PFT in the past, your previous results will also be compared with the latest data. If your results have changed, or if you have abnormal measurements, other tests may need to be conducted.

Why might I need one?

PFTs may be done as part of a routine physical, or it may be routine for coal miners and other employees who work in dangerous work environments. Your healthcare provider might also conduct a PFT in order to diagnose:

  • Respiratory infections
  • Allergies
  • Breathing problems
  • Asthma
  • Chronic bronchitis
  • Emphysema
  • Asbestosis (a lung disease caused by inhaling asbestos fibers)
  • Restrictive airway problems (via a scarring or inflammation of the lungs, tumors or scoliosis)
  • Scleroderma (a chronic tightening and hardening of the skin and connective tissues)
  • Sarcoidosis (the growth of tiny groups of inflammatory cells in the lungs and other parts of the body)

They can also be used to check lung function before a surgical procedure, but this is mainly for patients who have lung or heart issues or are smokers. If there is a different reason for ordering a PFT, your doctor will have that discussion with you.

What will happen during the procedure?

The procedure varies from patient to patient, depending on your condition and your provider’s methods. It may be an outpatient procedure allowing you to go home the same day or you may need to stay in the hospital for a day or two.

In most cases, you will be seated in a chair and a clip will be placed over your nose. This is done so that all of your breathing is done through your mouth. You will be given a sterile mouthpiece with a spirometer. A spirometer is an apparatus that measures how much air you inhale, how much you exhale and how quickly you exhale. You will put the mouthpiece into your mouth and you will be instructed to inhale and exhale in various ways. Some doctors may give you a bronchodilator after certain tests. A bronchodilator is a substance that helps to open up your airway passages, allowing you to breath easier. The tests will then be repeated after the bronchodilator sets in.

Questions or concerns about pulmonary function tests?

If you live in Encinitas or San Diego County, call North Coast Family Medical Group to discuss any questions or concerns that you have about pulmonary function tests. We can also discuss the risks with you. Call today at (760) 942-0118.