Emphysema is a respiratory disease that makes it hard to breathe.

Normally, when you take a breath, air travels from your nose and mouth through your windpipe and into the bronchi. These are small air passages that branch off into each lung. The bronchi branch further into thousands of smaller, thinner tubes that end in grape-like clusters of small, round air sacs called alveoli. b17ae613-f788-4cbb-940e-0c7461b9187516207267112597

Tiny blood vessels absorb oxygen from the air through the walls of the alveoli and deliver it to cells throughout the body. Carbon dioxide moves in the opposite direction. It passes out of the bloodstream, back into the alveoli, and is then eliminated from the body when you breathe out.

Emphysema destroys the walls between the alveoli. This leaves the lungs less able to absorb oxygen into the bloodstream and remove carbon dioxide from the blood.

Lung tissue also loses its resilience, which prevents it from stretching and contracting properly. When the lungs lack resilience, they cannot fully push out air. Instead, some air remains trapped in the air sacs.

Emphysema, along with chronic bronchitis, is one of the two most common forms of chronic obstructive pulmonary disease.

Smoking causes the vast majority of cases of emphysema.

Symptoms of emphysema

The main symptom of emphysema is breathlessness. At first, you have difficulty catching your breath during activity. Over time, you may feel breathless after taking just a few steps, or when sitting or lying down.

Other symptoms caused by emphysema include:

  • shortness of breath
  • wheezing
  • weight loss
  • loss of muscle
  • a barrel chest, resulting from overinflation of the lungs

Diagnosing emphysema

Your medical history and symptoms can alert your doctor to test you for emphysema.

Medical history and physical exam. Your doctor will ask whether you smoke. He or she will need to know how easily you become short of breath and when. Do you have trouble climbing stairs? How long can you walk before you have to stop and rest?

Your doctor then will examine you to look for typical signs of emphysema. This may include:

  • watching for shortness of breath when you perform simple activities, such as walking into the exam room
  • looking at the size and shape of your chest
  • looking at how your chest moves when you breathe
  • listening to your lungs for wheezing or loss of the normal breath sounds
  • checking your skin, lips and fingernails for a bluish tint that indicates low blood oxygen levels
  • checking your fingernails for an unusual curvature ("clubbing") that sometimes occurs with chronic lung disease

Pulmonary function tests. Pulmonary function tests show how well your lungs work. They are useful both to diagnose emphysema and to determine how far the disease has progressed. You will breathe in and out through a spirometer, a tube that is connected to various machines. These tests measure two things:

  • forced vital capacity (FVC) shows the maximum amount of air you can breathe out in one breath.
  • forced expiratory volume in one second (FEV1) is the maximum amount of air you can exhale in one second.

X-rays. If you have emphysema, your lungs may appear larger than normal on a chest x-ray and hold abnormally large amounts of air. Your diaphragm (the main muscle involved in breathing) may appear flattened.

Laboratory tests. Lab tests can show how much emphysema has affected your lungs' ability to take up oxygen and eliminate carbon dioxide.

Pulse oximetry. A probe on your finger measures how saturated your blood is with oxygen.

Arterial blood gas. This blood test measures how much oxygen and carbon dioxide are in your blood.

Treating emphysema


Don't smoke. If you smoke, quitting is the most important thing you can do to stop emphysema from getting worse.

Participate in pulmonary rehabilitation. Pulmonary rehabilitation is a form of physical therapy. It includes a structured exercise program combined with special breathing techniques, psychological support and education. It helps people with emphysema:

  • conserve energy
  • improve stamina
  • reduce breathlessness

Get vaccinated. If you have emphysema, ask your doctor about vaccinations against influenza (flu) and pneumococcal pneumonia. These vaccinations can help to prevent life-threatening respiratory infections in people with lung disease.


Medications and other treatments won't cure emphysema. But they can help you breathe well enough to remain active.

Bronchodilators open up the airways. They are the cornerstone of treatment. They reduce shortness of breath and increase capacity for exercise. Bronchodilators are usually inhaled.

Corticosteroids are powerful drugs that curb inflammation and help open airways. They are available in inhalers and as pills.

Antibiotics are used to treat lung infections caused by bacteria. People with emphysema often need antibiotics for respiratory infections.

Oxygen therapy

As emphysema becomes more severe, the oxygen level in your blood may become dangerously low. If this happens, breathing in extra oxygen can help you live longer. And it can help you avoid problems that can occur when your body isn't getting enough oxygen on its own.


Lung volume reduction surgery. This procedure involves removing some damaged lung tissue to give healthier lung tissue more room to expand and contract. It also lets the diaphragm work more effectively.

Lung transplant. A lung transplant may be an option for people with severe emphysema who are not expected to live more than two or three years.


As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.

No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

Free Healthbeat Signup

Get the latest in health news delivered to your inbox!

Sign Up
Harvard Health Publishing Logo

Thanks for visiting. Don't miss your FREE gift.

The Best Diets for Cognitive Fitness, is yours absolutely FREE when you sign up to receive Health Alerts from Harvard Medical School

Sign up to get tips for living a healthy lifestyle, with ways to fight inflammation and improve cognitive health, plus the latest advances in preventative medicine, diet and exercise, pain relief, blood pressure and cholesterol management, and more.

Harvard Health Publishing Logo

Health Alerts from Harvard Medical School

Get helpful tips and guidance for everything from fighting inflammation to finding the best diets for weight loss...from exercises to build a stronger core to advice on treating cataracts. PLUS, the latest news on medical advances and breakthroughs from Harvard Medical School experts.

BONUS! Sign up now and
get a FREE copy of the
Best Diets for Cognitive Fitness

Harvard Health Publishing Logo

Stay on top of latest health news from Harvard Medical School.

Plus, get a FREE copy of the Best Diets for Cognitive Fitness.