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  • A form of COPD caused by permanent damage to the lungs
  • Symptoms include shortness of breath, difficult catching breath after physical exertion, cough, wheezing
  • Treatment includes lifestyle changes, medications, pulmonary rehabilitation, supplemental oxygen, surgery, lung transplant, bronchoscopic interventions
  • Involves Pulmonology, Critical Care & Sleep Medicine; Chronic Obstructive Pulmonary Disease (COPD) Program



Emphysema is a form of chronic obstructive pulmonary disease, or COPD. Emphysema is caused by permanent damage to the lungs, making it hard for a person to breathe. The most common cause of this damage is smoking, although long-term exposure to chemicals or pollutants in the environment can also lead to emphysema.

About 15% of smokers are diagnosed with emphysema, typically in their 40s or 50s. A rare inherited condition known as alpha-1 antitrypsin (AAT) deficiency can predispose people, especially if they smoke, to developing early-onset emphysema.

Initially, people with emphysema may not realize that they have this condition because the disease is silent at first and symptoms only appear after more than half of the lung tissue has been damaged or destroyed. Over time, however, as breathing difficulties and other symptoms arise, people are prompted to seek help.

There is no cure for emphysema, but treatments are available that focus on helping patients breathe easier and improving their quality of life. In serious cases, emphysema can lead to life-threatening complications or death.

What is emphysema?

Emphysema is a type of chronic obstructive pulmonary disease (COPD). COPD is an umbrella term for various progressive lung diseases caused by damage to the lung tissue via smoking and other similar exposures over time, making breathing difficult. Since the most common cause of COPD is smoking, it is considered a preventable health condition.

When a healthy person inhales, the oxygen-rich air travels through the large airways (bronchi) and then smaller airways (bronchioles) that branch off of larger airways, and ultimately ends in numerous air sacs (alveoli). The air sac walls contain tiny blood vessels (capillaries) that enable oxygen to enter the bloodstream while letting carbon dioxide, a waste product of the body, to exit the bloodstream.

People with COPD experience damage to both their bronchioles (causing those to collapse upon exhalation) and alveoli (causing those to burst). These two processes cause air to be trapped in the lung and create large empty spaces typical of emphysema. The destruction of air sacs also damages the capillaries that enable oxygen and carbon dioxide to be exchanged in the lung. As a result, people with emphysema have trouble getting enough oxygen into their bloodstream and exhaling carbon dioxide, and feel short of breath.

What causes emphysema?

Emphysema arises when the lungs are damaged by repeated exposure to irritants. Common causes include:

  • Smoking
  • Vaping
  • Secondhand smoke
  • Air pollution
  • Exposure to smoke from fires (e.g., wood) used for cooking or heating
  • Chemical fumes at work
  • Dust inhalation at work
  • Chronic lung infections

Additionally, AAT deficiency, an inherited condition, can increase the risk of developing emphysema. The liver produces alpha-1 antitrypsin, or AAT, a protein that plays an important role in protecting the lungs from damage caused by enzymes called proteases, in particular one called neutrophil elastase.

Normally, neutrophil elastase helps the body fight against infections in the lungs. The enzyme works, in part, by destroying bacteria, but it can also damage lung tissue. AAT is another enzyme that works in the lung and liver tissue and limits the damaging effects of the neutrophil elastase on the lung tissue.

In people with AAT deficiency, there isn't enough AAT to prevent elastase from damaging lung tissue, resulting in emphysema. Individuals with this condition may get emphysema even if they do not smoke. But, since smoking raises neutrophil elastase levels—exacerbating the lung tissue damage—people with AAT deficiency who smoke typically develop emphysema earlier and with much higher severity than nonsmokers with this condition.

What are the symptoms of emphysema?

People with emphysema may not notice symptoms early on, despite already having lung damage. Once symptoms arise, they may include:

  • Shortness of breath
  • Difficulty catching breath after physical exertion
  • A deep cough that produces mucus
  • A cough that doesn’t fade, which worsens after a cold or other illness
  • Wheezing
  • A whistling noise when air is inhaled
  • Chest tightness
  • Mucus that is thick and difficult to cough up
  • Difficulty breathing while sitting or lying down
  • Sharp chest pain
  • Quick, shallow breathing
  • Swollen feet, ankles, or legs
  • Lips, fingers, or toes that appear blue or purple
  • Frequent nighttime awakenings
  • Frequent infections affecting the lungs
  • Weight loss

What are the risk factors for emphysema?

People, particularly older adults, are at increased risk of emphysema if they:

  • Smoke
  • Vape
  • Are exposed to secondhand smoke
  • Live in an area with air pollution
  • Are exposed to cooking fires
  • Breathe in chemical fumes
  • Are frequently exposed to dust in high amounts
  • Have chronic lung infections
  • Have Inherited AAT deficiency
  • Have a family history of emphysema, COPD, or other chronic respiratory conditions
  • Use intravenous recreational drugs
  • Have been diagnosed with HIV

How is emphysema diagnosed?

Before making a diagnosis of emphysema, a range of factors, including medical history, physical exam and diagnostic tests, have to be evaluated.

The evaluation starts from your medical history. When you share details about your personal medical history, tell your doctor if you smoke, vape, or live with a smoker, which would expose you to secondhand smoke. Smokers should provide information about how long they have smoked and how many packs they smoke daily. Also, tell the doctor if you’re exposed to fires, chemical fumes, or dust particles at work or at home. Your method of cooking (gas vs electric stove) may also be important.

Be sure to describe the symptoms you’re experiencing, such as shortness of breath and coughing up mucus, including details about their onset, what brings them on and how they go away, and how much physical activity you can do. Remember to mention how symptoms affect your quality of life. If you have difficulty breathing while lying in bed and that makes it difficult to sleep at night, share this information with the doctor.

During a physical exam, the doctor will listen to your lungs with a stethoscope to check for wheezing or mucus in the lungs. In another test, you will be asked to blow into a spirometer to determine if it takes you longer than the average of people in your age group to exhale, a hallmark of COPD. Doctors may also look for other signs, including bluish lips or unintentional weight loss.

To confirm the presence of emphysema, doctors may rely on one or more of the following diagnostic tests:

  • Lung function tests, which includes spirometry (above) and also determines how much air is trapped in your lungs after exhalation and how well the oxygen in the air enters your blood.
  • A chest X-ray, an imaging test that can show the presence of lung abnormalities, indicating emphysema
  • A pulse oximeter, which clips to your fingertip and measures your blood oxygen level, to see if your lungs and heart are sufficiently transferring oxygen from the air into your body.
  • Blood tests to measure the oxygen and carbon dioxide levels in your blood, check for alpha-1 antitrypsin deficiency (A1AD), or rule out other conditions
  • A computed tomography (CT) scan, a more detailed imaging of the lungs that more clearly shows if the airways and air sacs are affected by COPD.

How is emphysema treated?

Once emphysema occurs, there is no way to reverse the damage and, therefore, the condition is considered incurable. However, treatments are available that can help manage the condition or prevent it from worsening, the most important being smoking cessation.

Lifestyle changes:

  • Quitting smoking/vaping prevents emphysema from worsening and usually improves the symptoms. Also, avoiding secondhand smoke, air pollution, chemical fumes, and dust may have similar effects.
  • Starting an exercise plan, especially if you are physically inactive, will help strengthen the muscles you use for breathing and also strengthen your cardiovascular system to compensate for any respiratory defects.


Doctors may also prescribe the following medications:

  • Bronchodilators are prescription medications administered by an inhaler or a nebulizer that opens the airways to make breathing easier. There are both short- and long-acting bronchodilators; doctors may prescribe both simultaneously.
  • Phosphodiesterase inhibitors are medications that can dilate the airways, making it easier to breathe.
  • Anti-inflammatory medications. Corticosteroids and other similar therapies may be prescribed to people with emphysema. They limit breathing difficulties and improve quality of life. Corticosteroids may be inhaled or taken orally.
  • Antibiotics. When people with emphysema experience flare-ups of symptoms due to bacterial chest infections, antibiotics will be prescribed to help reduce symptoms.
  • Mucolytics. These medications thin thickened mucus in the airways, making it easier to cough up mucus.
  • Alpha-1 antitrypsin deficiency (A1AD) treatments. For those with this rare genetic disorder, doctors prescribe intravenous augmentation therapy by infusion of the purified Alpha-1 antitrypsin protein.

Therapies. The following treatments may also be recommended:

  • Supplemental oxygen, which may be prescribed to those whose blood-oxygen levels fall below 88%, to increase the percentage of oxygen in the blood above 90%.
  • Pulmonary rehabilitation. These programs teach breathing exercises and techniques to avoid shortness of breath in certain situations, and are a very important option in patients with advanced disease.

Surgery. Different surgical options may ease emphysema symptoms for people with severe emphysema. After removing diseased lung tissue, the remaining lung tissue will be able to function more efficiently.

Bronchoscopic interventions: Similarly, recent studies have shown that closing up the emphysema in the lung with a valve or a coil may be helpful for some patients with severe disease. These interventions are done by bronchoscopy (i.e., sending a camera through the trachea).

Lung transplant. In certain circumstances, people with severe emphysema may need a transplant to improve their breathing ability.

What is the outlook for people with emphysema?

Lung damage caused by emphysema is permanent and the condition is considered incurable. However, a lot can be done to lessen the symptoms, improve quality of life, and decrease the risk of fatal complications. The most important of these interventions is prevention of further damage by avoiding smoking.

For some people, complications of emphysema can cause death. Individuals are more likely to experience life-threatening complications, including pneumonia or respiratory failure, if they have genetic or chronic conditions such as:

  • Alpha-1 antitrypsin deficiency (A1AD)
  • Asthma
  • Heart disease
  • High blood pressure (hypertension)
  • Diabetes
  • Bronchiectasis, a rare condition that causes irreversible damage to the lung’s airways

What makes Yale unique in its treatment of emphysema?

“At Yale COPD patients, including patients with emphysema, are managed at a subspecialty clinic, staffed by a team of pulmonary specialists, pharmacists, respiratory nurses, and respiratory therapists,” says Yale Medicine pulmonologist Sayedtaghi “Shervin” Takyar, MD, PhD. “Referrals are made to the Sleep clinic, Pulmonary rehabilitation, Smoking cessation clinic, Nutrition, and other specialties such as Allergy and Immunology, Ear Nose and Throat, Cardiology, and Rheumatology, all of which can be found within the Yale Health system. Also, specialty referrals for interventions [surgery and bronchoscopy] are made to the Interventional pulmonology and Thoracic surgery clinics.”

Patients referred to the Yale COPD clinic go through a comprehensive evaluation for every aspect of their breathing quality and the extent of disease progression, appropriateness of their medication, and the mode of delivery—for instance, inhaler vs nebulized therapy, need for oxygen or other supplemental therapies, and most importantly, their status and attitude about smoking, he adds. “This multidisciplinary approach provides the patient with a variety of options, from behavioral support for quitting to surgical interventions and transplant. The main focus of this comprehensive program, though, is understanding the unique needs of each patient and tailoring therapies and interventions accordingly,” he says. “Smoking is one of the most challenging forms of addiction, and emphysema is among the deadliest conditions currently affecting Americans. We, therefore, believe that finding the path back to health is only possible through a close collaboration between the patients and the caregivers.”