Pulmonary Function Test (PFT)

Pulmonary function tests (PFTs) are a group of breathing tests that measure how much air your lungs can hold, how fast you can move air in and out, and how well oxygen passes from your lungs into your blood. They are painless and usually done in a hospital lab or pulmonologist's office using a mouthpiece connected to a machine. Results are reported as percentages of what would be expected for a person of your age, sex, height, and race.

Origin

Spirometry, the oldest component of PFTs, was developed by British surgeon John Hutchinson in 1846 when he introduced the spirometer to measure "vital capacity." Diffusing capacity testing was added in the early 20th century, and modern PFT batteries combining spirometry, lung volumes, and gas exchange became standard in pulmonary medicine by the 1950s–60s.

Significance in Asbestos Context

PFTs are one of the central tools doctors use to measure how much asbestos has damaged your lungs. In asbestosis, PFTs typically show a restrictive pattern (reduced lung volumes and reduced diffusing capacity, or DLCO) because scarring stiffens the lung tissue. In pleural disease or mesothelioma, restriction often comes from the lung being encased by thickened pleura or fluid. The numerical results (FVC, FEV1, TLC, and DLCO expressed as percent predicted) are frequently used to support disability ratings, workers' compensation claims, and trust fund claims, and many asbestos trusts have specific PFT thresholds (for example, FVC or DLCO below a certain percent predicted) that must be met to qualify for higher payment tiers.

Example Sentence

Her pulmonologist ordered repeat PFTs every six months to track whether her asbestosis was progressing, and the declining DLCO became key evidence in her trust claim.

Related Terms

Spirometry, DLCO (Diffusing Capacity), FVC, Restrictive Lung Disease, Asbestosis, Pleural Plaques, Diffuse Pleural Thickening, Vital Capacity

Notes

• Ask your pulmonologist for a complete PFT battery. Spirometry alone is not enough; insist on lung volumes (TLC) and DLCO, since DLCO is often the earliest abnormality in asbestos-related lung disease.
• Request and keep copies of every PFT report, including the raw numbers and percent predicted values, not just the doctor's summary. Trusts and courts want the actual numerical data.
• Effort matters: tell the technician if you are coughing, in pain, or short of breath, because poor effort can falsely lower your scores and hurt both your treatment plan and your claim.
• Be aware that in 2023 major pulmonary societies recommended removing race-based adjustments from PFT reference equations; if your older tests used race correction, ask whether reinterpretation could change your impairment rating.
• Serial PFTs (done over time) are more meaningful than a single test. Preserve old results from any prior employer, VA, or screening program.