Hyperinflation of the lungs (a.k.a. pulmonary hyperinflation) occurs when an increase in lung volume prevents efficient airflow in the body. Essentially, air gets trapped, either because of blocked airways or compromised air sacs, causing the lungs to retain air. This occurs with lung diseases such as chronic obstructive lung disease (COPD) and emphysema. Aside from breathing difficulties, this condition can also lead to heart disease.

Diagnosis of lung hyperinflation involves imaging studies and may also include tests of respiratory and cardiac function. Medications can help relieve the effects, and surgical treatment (lung-volume reduction) may be used in severe cases.

Symptoms

It can be hard to distinguish the effects of hyperinflated lungs from the symptoms of the lung disease that caused it.

If you have hyperinflated lungs, you may experience:

Difficulty inhaling
Struggling to breath
Shortness of breath
Fatigue
Low energy

Exercise intolerance is very common with lung hyperinflation. You may feel very short of breath or unusually exhausted during or after physical activity, be it a walk through the neighborhood or even cleaning your home.

When lung hyperinflation is mild or just starting to develop, the symptoms may only be noticed during physical activity or exercise.

Complications

The biggest worry about hyperinflation of the lungs is that, over time, it affects heart function. One of the most common consequences is decreased blood volume in the left ventricle of the heart. When this happens, the heart pumps less oxygen-rich blood through the body, leading to exhaustion and fatigue. It also compresses the heart and may increase the risk of heart failure.

Causes

With every breath you take and exhale, your lungs inflate and deflate. But in cases of hyperinflation, the lungs enlarge more than they should with each inhalation. With every exhalation, the lungs do not deflate as much as they should.

The expanded lungs, then, become larger than healthy lungs—but they do not have enough space for all that air.

Lung disease makes it difficult for oxygen to travel efficiently between the alveoli (air pockets) and the nearby capillaries (tiny blood vessels) that lead to the heart. Lung hyperinflation makes the situation even worse.

There are two ways that lung disease causes hyperinflation to develop—dynamic hyperinflation and static hyperinflation.

Dynamic Hyperinflation

Lung disease is characterized by inflammation, mucus plugging, and scarring, all of which narrow the airways. When this happens, it takes more time to fully exhale. Dynamic hyperinflation is when you begin to inhale before fully exhaling and the lungs expand beyond their normal range.

Dynamic hyperinflation, the more common of the two types of hyperinflation, is related to active lung movements.

Studies have shown that dynamic hyperinflation not only affects the lungs but makes the cardiovascular system less effective during exercise, reducing the heart rate, blood pressure, and oxygen pulse (the amount of oxygen consumed per heartbeat).

Static Hyperinflation

The airways of healthy lungs have elastic tissue that helps them expand and deflate efficiently. Static hyperinflation occurs when lung disease reduces the inherent elasticity of the airways. With each expiration, the alveoli do not deflate as they should. The decreased elasticity of the bronchi may prevent air from exiting the lungs efficiently, adding to alveolar expansion.

Static hyperinflation is increased during severe COPD exacerbations and often requires hospitalization to restore the inspiratory capacity (the volume of air that can be inhaled in a normal, relaxed state).

People with COPD can develop dynamic lung hyperinflation, static lung hyperinflation, or a combination of both.

Diagnosis

Hyperinflated lungs don't cause distinct symptoms. They also don't cause any change in a person's physical appearance. Your doctor may notice that your breathing is consistent with lung hyperinflation when listening to your chest examination with a stethoscope, but other changes caused by your underlying lung disease are likely to be more prominent.

Because of the non-specificity of symptoms, hyperinflation of the lungs can sometimes be tricky to diagnose. Some studies have suggested that up to 19.8% of people with COPD are initially misdiagnosed by their primary care physician and require a specialist pulmonologist to make the correct diagnosis.

In general, lung hyperinflation is detected with imaging tests, and the condition may be detected at an early or late stage. Complications of lung hyperinflation can be evaluated with tests such as an echocardiogram, which is a test of heart function.

Imaging Tests

Hyperinflated lungs can be identified on a chest X-ray, as well as a chest computed tomography (CT) scan. The radiologist will likely take images both during inspiration and expiration.

Often, however, the condition is detected incidentally, meaning that lung hyperinflation was noticed on an imaging test done for another reason.

Respiratory Tests

Your medical team may measure your air volume with pulmonary function tests. You breathe in and out during this process, and a machine measures your air volume.

With lung hyperinflation, the total lung capacity tends to be lower than expected for your age category, while the residual volume (the amount of air remaining in the lungs) tends to be higher.

Cardiac Evaluation

Because lung hyperinflation can cause heart failure, your doctor may also order some cardiac tests for you—especially if you have symptoms of heart disease.

An echocardiogram is a non-invasive heart ultrasound test that can be used to visualize the movements of your heart. It evaluates heart function, measures blood volume as it flows through the heart chambers, and can detect signs of heart failure.

Treatment

There are several treatments used in managing lung hyperinflation. Medication can help with airway management. Lung volume reduction surgery is another approach. Surgery is riskier than medication, but in some cases, it is the most effective option.

Bronchodilators

Medications used to widen the bronchi can help reduce lung hyperinflation. Long-acting bronchodilators work by expanding the bronchi for a sustained period of time. These medications can help improve the effects of lung hyperinflation.

Bronchodilators reduce the impact of dynamic hyperventilation because the expansion of the bronchi provides space for air to exit the lungs.

Lung-Volume Reduction Surgery

Within your lungs, areas of severe lung disease are not effective when it comes to oxygen exchange. They take up space, compressing healthy lung tissue and the airway passages within them.

The surgical removal of unhealthy lung tissue, called lung-volume reduction surgery, aims to alleviate this burden. It permits healthy areas of the lung to have space and can promote the growth of healthy tissue.

In general, lung-volume reduction surgery is not considered a viable option if the lung damage is extensive. It is usually reserved for when the lung injury is limited or unilateral (involving one lung only).

A Word From Verywell

Lung hyperinflation is one of the most common effects of chronic lung disease. Enlarged lungs interfere with effective oxygen exchange. Over time, heart complications can develop. If you have a chronic lung disease, your medical team is likely to look for signs of lung hyperinflation on your diagnostic tests. Be sure to avoid exacerbating factors, such as smoking and exposure to pollutants.