PFTs Don’t Know How Important They Are

Pulmonary function tests are strange.

They’re used to measure how well the lungs are working.

Most of the time, they don’t matter that much. The numbers are a little off. The effort isn’t perfect. The interpretation could go either way. Nothing really changes.

But sometimes they matter a lot. A surgical decision. A diagnosis. A trajectory. And in those moments, the result suddenly carries weight.

The problem is that pulmonary function tests don’t tell you which situation you’re in.

They present the same way every time. A clean report. Precise numbers. A definitive interpretation. Whether the result is trivial or consequential, it looks the same.

So we treat them like they’re always important. And we trust them like they’re always reliable.

But they’re not.

PFTs are low-stakes most of the time, high-consequence some of the time, and treated like high-certainty all of the time.

That’s the problem.