An iron lung wasn’t designed to “run out” after a set time—the machine can keep working for decades with maintenance, so the real limit is how long the person needs it, not how long it lasts mechanically.

How long do people stay in an iron lung?

  • Most polio patients used an iron lung for only a few weeks to a few months , just long enough for their breathing muscles to recover.
  • If polio permanently paralyzed the chest muscles, some patients needed it for life.
  • One Australian woman, June Margaret Middleton, spent more than 60 years living in an iron lung, and was recognized for the longest time spent in one.
  • American survivor Paul Alexander used an iron lung for around 70 years , making him the longest surviving long‑term iron lung user on record.

What was it originally meant for?

  • The iron lung was intended as a short‑term treatment, roughly two weeks , to let the body recover from acute polio.
  • In practice, severe cases and permanent paralysis turned it into a long‑term life-support system for a small number of people.

So, in human terms, an iron lung can keep someone alive for many decades if it’s maintained and if no alternative breathing support is available.

TL;DR: Most people used an iron lung for weeks or months, but a few have lived in one for over 60–70 years.

Information gathered from public forums or data available on the internet and portrayed here.