How and why do lungs collapse?


If breathing is controlled by the diaphragm, wouldn’t trying to take a deep breath just create the necessary vacuum inside the chest cavity to allow air to reenter a lung that had all the air forced out of it?

In: 1

If air gets in between the chest wall and lung, the negative pressure barrier between the chest wall and lung is no longer holding the lung tissue apart from itself suspended by the chest wall. Lungs are soggy and flappy, and want to stick together like wet Saran wrap. Every time a person breathes, the pressure is more equalized if there’s a consistent leak (like from a ruptured lung bit or trauma, maybe) and the other lung inflates disproportionately, squishing the compromised lung even flatter to the point that the windpipe can become asymmetrical in the neck, pointing toward the leaky side.

You need the negative pressure to pull on the outside of the lungs’ surface and inflate it. It’s not like blowing up a balloon, it’s sucking a balloon full of air with negative pressure.

In my case my collapsed lung was a result of being infected top and bottom. That made the outside of the lung fill with fluid. At least that’s what they said after surgery.

Imagine a balloon in a glass tube. The top of the balloon is attached to the top of the tube, and the bottom of the tube has a plunger that can go in and out. If you pull the plunger out, it creates a vacuum and the balloon inflates. When you push the plunger back, the balloon deflates.

Now, put a hole in the balloon, or in the glass tube. Now, no matter what you do with the plunger, the balloon isn’t going to inflate. That’s what’s happening with a collapsed lung.