Atelectasis

Atelectasis (pronounced at-uh-LEK-tuh-sis) is the collapse of one or more parts of the lung. It specifically affects the small air sacs called alveoli.

When you breathe in, your lungs fill up with air. The air travels to sacs in your lungs (alveoli), where the oxygen moves into your blood. The blood delivers the oxygen to organs and tissues throughout your body.

If you don’t have enough air coming in to inflate your alveoli or if outside pressure is pushing on them, they can collapse (atelectasis). Atelectasis can happen in a small area or the whole lung. If enough of your lung is affected, your blood may not receive enough oxygen, which can cause health issues.

What’s the difference between atelectasis and pneumothorax?

Atelectasis is a condition where alveoli in your lung or a part of your lung deflates, causing a partial or complete collapsed lung. Pneumothorax is a condition where air leaks into the space around your lung, compressing it and causing it to collapse.

What does atelectasis indicate?

If you haven’t had a chest or abdominal surgery recently, atelectasis can indicate an obstruction of your airway that’s causing a partial or complete collapse of your lung.

Who is at risk for atelectasis?

You’re at a higher risk for atelectasis if you have:

• Had chest or abdominal surgery that requires medication to keep you relaxed or asleep (anesthesia), preventing you from taking deep breaths.
• A condition that blocks the small airways (branches) in your lungs, preventing normal lung expansion.
• A chest injury or rib fracture that causes severe pain. This may keep you from being able to take deep breaths.
• Had smoke exposure.

What are the three types of atelectasis?

There are three main types of atelectasis: compressive, resorptive (obstructive) and contraction.

Compressive atelectasis

Compressive atelectasis is when something around your lung — like fluid, air, blood or a tumor — pushes against it, causing it to collapse.

Resorptive/obstructive atelectasis

Resorptive atelectasis happens when the oxygen and carbon dioxide in your alveoli move into your bloodstream and no new air moves in. This causes your alveoli to collapse. Surgery that requires anesthesia is a common cause of resorptive atelectasis.

Something blocking the inside of your lung, keeping air from coming into the alveoli, can also cause resorptive atelectasis. Also called obstructive atelectasis, the blockage can be mucus, a tumor or an object that you accidentally inhaled.

Contraction atelectasis

Lung scarring (fibrosis) causes contraction atelectasis. Scarring keeps the alveoli from opening properly.

Other types of atelectasis

Newborns, particularly premature newborns, or people with acute respiratory distress syndrome (ARDS) can have an uncommon type of atelectasis called patchy atelectasis. Patchy atelectasis happens when you don’t have enough of a protein in your lungs that helps keep them from collapsing (surfactant).

Other types of atelectasis (bibasilar atelectasis, rounded atelectasis, gravity-dependent atelectasis and subsegmental atelectasis) describe the location, appearance or severity of the collapse.