What Are Hyperinflated Lungs?

Medically Reviewed by Paul Boyce, MD on April 18, 2022
3 min read

Hyperinflated lungs are larger-than-normal lungs as a result of trapped air. It happens when you can’t exhale, or push out all of the air that’s in your lungs. The air gets trapped and takes up space, which can make it harder to get fresh air into your body.

Your lungs try to fix this by taking in more and more air. This overinflates, or “hyperinflates,” your lung tissue and makes it less stretchy over time. Eventually, your lung tissue may start to die.

A hard time breathing when you walk up a flight of stairs or exercise is the main symptom of hyperinflated lungs. It’s called dynamic hyperinflation.

Overextension can cause your lungs to be less flexible even when you’re at rest, or not doing anything. That’s called static hyperinflation. You simply may not be able to exhale as much air with each breath. That leaves more air in your lungs before you breathe in again, which slowly over-expands and damages your lungs.

Eventually, your muscles and even your ribs might start to stretch and separate to make room for the larger lungs. This can also push on your diaphragm, which might flatten, lose tone, and stop working properly. This makes it even harder to take in and push out air.

Anything that limits the flow of air out of your lungs can lead to hyperinflation.

The most common culprit is chronic obstructive pulmonary disease, or COPD, mainly caused by smoking. COPD is made up of one or more of three serious lung illnesses that make it harder to breathe and get worse over time:

  • Emphysema: Slowly destroys tiny air sacs (alveoli) in your lungs that bring in needed oxygen and send out carbon dioxide you need to get rid of.
  • Chronic bronchitis: Inflames small airway tubes called bronchi over the long term.
  • Chronic obstructive asthma: Narrows airways and causes wheezing, coughing, and breathing problems that don’t improve over time.

Normal asthma (not linked to COPD) can also limit airflow and enlarge your lungs. Less common conditions that can limit airflow and lead to hyperinflated lungs include:


The doctor will talk to you about your medical history and listen to your chest for any strange sounds. They’ll ask about your symptoms, like whether it’s harder to breathe during certain activities. The doctor may want to test your lung capacity while you exercise.

Your doctor may also want to do:

  • X-rays
  • A CT scan
  • Tests to see how well your heart and lungs work

Treatment depends in large part on what’s causing your hyperinflated lungs. Your doctor may prescribe a type of medicine called a bronchodilator. It can open up your airways and help reverse the effects of hyperinflated lungs by allowing the trapped air to escape. Certain types of exercise might also help. Extra oxygen that you breathe in through a mask or through tubes that go into your nostrils might also help. In some cases, your doctor might suggest surgery to reduce the size of one or both of your lungs.