Air travels to the lungs by means of two major passageways called bronchi. These large passages further divide into tens of thousands of smaller airway routes called branchioles. At the end of the branchioles are groups of alveoli, or air sacs. There are about 300 million alveoli in each lung. During the intake of breath, these tiny, balloon-like air sacs stretch and disperse oxygen through their thin walls into the blood. As a person exhales, the sacs retract and expel the used air (carbon dioxide) from the body.

Emphysema is a chronic disease that interferes with normal breathing. It occurs when the delicate air sac walls (which are highly elastic) become inflamed, causing them to lose their natural elasticity. They overexpand and lose the ability to fill up and contract properly. As air gets trapped in these tiny sacs, some rupture to form one large air space instead of many small ones. The trapped air cannot be fully released when a patient exhales, and breathing then becomes more and more labored.


The first sign of the disease is a sensation of not being able to get enough air. In the initial stages of emphysema, shortness of breath (dyspnea) may be noticeable only during activity. In later stages, a person may struggle for air even when sitting quietly or lying down. 

Other symptoms include:

  • A mild but constant cough
  • Wheezing
  • Continuous production of mucus or phlegm
  • Feeling tired, due to less oxygen getting to the body
  • Poor appetite. Eating becomes more of a strain because it takes more breath.
  • Weight loss, caused by reduced interest in eating


Causes and Risk Factors

Smoking (including cigarettes, cigars and pipes) is the number one cause of emphysema, accounting for about 80% of all cases. Smoke damages the miniscule hairs in the bronchial tubes called cilia. Cilia are responsible for keeping irritating substances and germs out of air passages. When air passages are not regularly cleaned out, they become inflamed and the elastic fibers break down. 

Other causes of emphysema are:

  • Air pollution, both indoors and outdoors
  • Chemical fumes and irritants found in certain workplace settings
  • Lack of a lung-protecting protein called alpha-1-antitrypsin. This is a genetic condition.
  • Exposure to second-hand smoke also contributes to the onset of emphysema

At highest risk for emphysema are people over 40 years old who have smoked for long periods of their life. Emphysema patients have an increased risk of other pulmonary diseases, such as bronchitis, pneumonia, asthma and lung cancer.


After taking a careful medical history, paying special attention to the length of time the person has been smoking and how severe symptoms are, the doctor will examine the chest and lungs. He or she will also check the heart to see if emphysema has caused cardiac strain. Tests will be done to determine how well or poorly the lungs are working.

Depending on the stage of the disease, the doctor may also conduct other tests, including:

  • Measuring the quantity of oxygen in the blood
  • Determining the amounts of oxygen and carbon dioxide in the blood (arterial blood gas test)
  • Air capacity breathing test, to measure blockage of air passages
  • X-rays
  • CAT scans


Since the lung damage already caused by emphysema cannot be reversed, the very first treatment is to cease all smoking. This can stop or greatly slow the further progress of the disease. Other options for treating emphysema are:

  • Bronchodilators, which are medications that can help clear tightened airways by relaxing the muscles surrounding the passages
  • Corticosteroids, which are inhaled medicine used to reduce inflammation of the fragile linings of the air passages
  • Flu and pneumonia shots to avoid complications
  • Antibiotics to fight infections
  • Protein infusions for people with a genetically caused form of emphysema
  • Supplemental oxygen, which comes in three forms: compressed gas, cold liquid and an oxygen concentrator. All are designed for at-home use by the patient.
  • Lung volume reduction surgery
  • Transplantation, a complex surgery in which the patient's diseased lung is removed and replaced with a donor's lung