Pulmonary function tests

Pulmonary function tests (PFTs) are tests that show how well your lungs are working. The tests measure lung volume, capacity, rates of flow, and gas exchange. This information can help your healthcare provider diagnose and decide the treatment of certain lung disorders.

Types of PFTs

• Spirometry: Measures how much air you can exhale and how quickly you can empty your lungs
• Body plethysmography: Measures how much air you can hold in your lungs after a deep breath
• Diffusion capacity: Measures how well your lungs move oxygen into your blood
• Pulmonary exercise tests: Measures how well your lungs work when you're active
• Arterial blood gases (ABGs): Measures the oxygen, carbon dioxide, and pH levels in your blood

How PFTs are performed

• You may be asked to breathe into a mouthpiece that's connected to a machine
• You may be asked to sit in a clear box while breathing into a mouthpiece
• You may be asked to blow out as hard and as fast as you can

What is the Pulmonary Function Test (PFT) used for?

• Assess patients before surgery
• Monitoring lung disease progression
• Follow up on the efficacy of the treatment
• If your symptoms indicate a lung condition
• To assess your lung function before surgery
• Check for possible toxic side effects of certain drugs (such as amiodarone, an antiarrhythmic)
• Monitoring chronic lung diseases, such as asthma or chronic obstructive pulmonary disease (COPD)
• Examine respiratory symptoms (e.g. wheezing, cyanosis, dyspnea) for evidence of respiratory disease

Why do I need a Pulmonary Function Test (PFT)?

• History of asthma
• Infections of the respiratory system
• Inhaling asbestos fibers at workplace causing asbestosis, a lung disease
• An injury to the chest or a recent surgery that causes trouble breathing
• Lung conditions like bronchiectasis, emphysema, or chronic bronchitis
• Scleroderma makes the connective tissue thicken and harden
• Airway restriction due to scoliosis, tumors, or inflammation or scarring of the lungs