What is emphysema?

Emphysema is a type of chronic obstructive pulmonary disease. The air sacs in the lungs become damaged and stretched. This results in a chronic cough and difficulty breathing.

Smoking is the most common cause, but emphysema can also be genetic. There is no cure, but quitting smoking can stop emphysema from getting worse.

In the United States (U.S.), 3.5 million people, or 1.5 percent of the population, received a diagnosis of emphysema in 2016. The number of deaths involving emphysema was 7,455, or 2.3 people in every 100,000.

Fast facts on emphysema

Here are some key points about emphysema. More information is in the body of this article.

• Most cases of emphysema are due to cigarette smoking.
• Shortness of breath and cough are the main symptoms of emphysema.
• Doctors diagnose COPD and emphysema with lung function tests that measure lung capacity.
• Treatment includes medications, the use of an inhaler, respiratory assistance and possibly surgery.
• Treatment does not halt or reverse lung damage, but it can ease symptoms and prevent attacks.
• Vaccinations can help prevent additional diseases that could become dangerous alongside emphysema.

What is emphysema?

Smoking is one of the key triggers of emphysema in those who are genetically predisposed to the condition.

Emphysema is a type of chronic obstructive pulmonary disease (COPD). It involves the loss of elasticity and enlargement of the air sacs in the lung.

The alveoli at the end of the bronchioles of the lung become enlarged because their walls break down or the air sacs are destroyed, narrowed, collapsed, stretched, or over-inflated.

Having fewer and larger damaged sacs means there is a reduced surface area for the exchange of oxygen into the blood and carbon dioxide out of it.

The damage is permanent. The ability to breathe properly cannot be fully recovered.

Symptoms

Two of the key symptoms of emphysema are shortness of breath and a chronic cough. These appear in the early stages.

A person with shortness of breath, or dyspnea, feels being unable to catch a breath.

This may start only during physical exertion, but as the disease progresses, it can start to happen during rest, too.

Emphysema and COPD develop over a number of years.

In the later stages, the person may have:

A chronic cough is one of the early signs of emphysema, alongside shortness of breath.

• frequent lung infections
• a lot of mucus
• wheezing
• reduced appetite and weight loss
• fatigue
• blue-tinged lips or fingernail beds, or cyanosis, due to a lack of oxygen
• anxiety and depression
• sleep problems
• morning headaches due to a lack of oxygen, when breathing at night is difficult

Other conditions share many of the symptoms of emphysema and COPD, so it is important to seek medical advice.

Treatment

Treatment of COPD and emphysema aims to stabilize the condition and prevent complications through the use of medication and supportive therapy.

Supportive therapy includes oxygen therapy and help with smoking cessation.

Drug therapies

The main type of medication used for COPD and emphysema are inhaled bronchodilators to relieve symptoms.

These help by relaxing and opening the air passages in the lungs.

Bronchodilators that are supplied though the inhalers include:

• Beta-agonists, which relax bronchial smooth muscle and increase mucociliary clearance
• Anticholinergics, or antimuscarinics, which relax bronchial smooth muscle.

These drugs are equally effective when regularly used to improve lung function and increase exercise capacity.

There are short-acting and long-acting drugs, and these can be combined.

The choice depends on individual factors, preferences, and symptoms.

Examples include albuterol, formoterol, indacaterol, and salmeterol.

Corticosteroid drugs, such as fluticasone, may also help. The steroids are inhaled as an aerosol spray. They can help relieve symptoms of emphysema associated with asthma and bronchitis.

Corticosteroids may help people with poorly controlled symptoms who regularly experience exacerbations despite using a bronchodilator.

In patients who continue to smoke, corticosteroids do not alter the course of the disease, but they can relieve symptoms and improve short-term lung function in some patients.

Used alongside bronchodilators, they can reduce the frequency of attacks.

However, there is a long-term risk of side-effects that include osteoporosis and cataract formation.

Oxygen therapy

Oxygen therapy can greatly improve the quality of life for those with emphysema.

As emphysema progresses and respiratory function declines, independent breathing becomes more difficult.

Oxygen therapy improves oxygen delivery to the lungs. Oxygen can be supplemented by using a range of devices, some of them for home use.

Options include electrically driven oxygen concentrators, liquid oxygen systems, or cylinders of compressed gas, depending on needs and how much time the person spends outdoors or at home.

Oxygen therapy can be administered 24 hours a day or 12 hours at night.

It prolongs life for people with advanced COPD and emphysema.

Patients will be monitored for oxygen saturation to prevent oxygen toxicity.

Air travel may create the need for supplemental oxygen due to the lower flight cabin air pressure.

Surgery

People with severe emphysema sometimes undergo surgery to reduce lung volume or carry out a lung transplantation.

Lung volume reduction surgery removes small wedges of the damaged, emphysematous, lung tissue.

This is thought to enhance lung recoil and to improve the function of the diaphragm. In severe cases, this can improve lung function, exercise tolerance, and quality of life.

Lung transplantation improves quality of life, but not life-expectancy, for people with severe emphysema.

Lifelong drug therapy is necessary to prevent the immune system from rejecting the new tissue. One or both lungs may be transplanted.

Treatment of exacerbations

Complications can be managed using drug and oxygen therapy. Antibiotics can help in cases of bacterial infection.

Most exacerbations are treated with corticosteroid drugs, such as prednisone, and oxygen therapy.

Opioid drugs may relieve severe coughing and pain may be relieved by opioid drugs.

In 2014, scientists at the University of Texas Medical Branch in Galveston succeeded in growing human lungs using stem cells. In the future, this could offer hope for people with emphysema and other lung conditions.

Pulmonary rehabilitation and lifestyle management

Pulmonary rehabilitation is a program of care for people with emphysema.

It aims to help people improve their lifestyle by quitting smoking, following a healthful diet, and getting some exercise.

Drinking plenty of water can help keep the airways clear by loosening the mucus.

In winter, avoiding cold air can prevent muscular spasms. A scarf around the mouth or a cold-air face mask may help.

These changes may not alter the overall course of the illness, but they can help people live with the condition, and improve exercise capacity and quality of life.

Exercises that can help improve breathing include diaphragmatic breathing, purse-lip breathing, and deep breathing.

Causes

Cigarette smoking is responsible for at least 85 percent of cases of emphysema and COPD.

However, not all smokers will develop it, only those who are genetically susceptible.

Other inhaled toxins that can lead to emphysema and COPD include work-related ones. In some countries, smoke from indoor cooking and heating is the main cause.

Other contributory risk factors are:

• low body weight
• air pollution
• occupational dust, such as mineral dust or cotton dust
• inhaled chemicals, including coal, grains, isocyanates, cadmium
• childhood respiratory disorders, either a viral infection, or possibly asthma

Exposure to passive cigarette smoke is thought to be a minor contributor.

Some people have a deficiency of a protein, α1-antitrypsin. This is a genetic factor that can lead to a rare form of emphysema.

α1-antitrypsin protects the lungs against the destruction of alveolar tissue by neutrophil elastase.

This deficiency is congenital. People are born with it. These people can develop emphysema at a relatively early age, without ever smoking.

Smoking does, however, accelerate emphysema in people who are genetically susceptible.

Emphysema is not contagious. One person cannot catch it from another.

Types

Emphysema is a type of chronic obstructive pulmonary disease (COPD), and it can be classified into different types, depending on which part of the lungs is affected.

The different types are:

• paraseptal
• centrilobular, affecting mainly the upper lobes; this is most common in smokers
• panlobular, affecting both paraseptal and centrilobular areas

Stages

The stages of emphysema have been described by the Global Initiative for Chronic Obstructive Lung Disease (GOLD).

The stages are based on forced expiratory volume in 1 second (FEV1).

• Very mild or Stage 1: FEV1 is about 80 percent of normal
• Moderate or Stage 2: FEV1 is between 50 and 80 percent of normal
• Severe or Stage 3: FEV1 is between 30 and 50 percent of normal
• Very severe or Stage 4: FEV1 is lower than in Stage 3, or the same as Stage 3 but with low blood oxygen levels

The stages help describe the condition, but they cannot predict how long a person is likely to survive. Doctors can carry out tests to know more about how serious a person's condition is.

Diagnosis

A doctor will carry out a physical examination and ask the patient about their symptoms and medical history.

Some diagnostic tests may also be used, to confirm that the patient has emphysema rather than asthma and heart failure.

If the patient has never smoked, a test may be carried out to see if the person has an α1-antitrypsin deficiency.

Lung function tests

Lung function tests are used to confirm a diagnosis of emphysema, to monitor disease progression, and to assess response to treatment.

They measure the capacity of the lungs to exchange respiratory gases and include spirometry.

Spirometry assesses airflow obstruction. It takes measurements according to the reduction in forced expiratory volume after bronchodilator treatment.

In this test, patients blow as fast and hard as possible into a tube. The tube is attached to a machine that measures the volume and speed of air blown out.

Forced expiratory volume in one second is abbreviated to FEV.

The four stages of COPD from mild to severe are determined by FEV.

Other tests

Other tests used by doctors in the process of diagnosing COPD and emphysema include:

• imaging, such as a chest X-ray or CT scan of the lungs
• arterial blood gas analysis to assess oxygen exchange

Prevention

Avoiding or quitting smoking is the best way to prevent emphysema or stop it from getting worse.

Vaccination

Vaccination can help prevent COPD and emphysema from getting worse.

An annual flu immunization is required, and a 5-yearly one against pneumonia may be recommended.

Nutrition

Reduced lung capacity places higher energy demand on daily activities, so people with emphysema can be at risk of weight loss and nutritional deficiency.

Some people with emphysema are overweight or obese, and they are encouraged to lose weight, as these conditions can lead to further ill health.

A healthful diet with plenty of fresh fruits, vegetables, and wholegrains and a low intake of fat and sugar is important.