There are several stages of emphysema. Each can help show how severe the disease is in a person. In general, stages range from mild to very severe and are based at least in part on the testing of a person’s lung function, though the exact name, number, and determination of stages may depend on the staging system used. Stages of emphysema are often used to help determine treatment and monitor the progression of the disease.
Emphysema is a lung disease that affects a person’s ability to breathe and circulate oxygen throughout the body. In most cases, it occurs as part of a condition known as chronic obstructive pulmonary disease (COPD), which is commonly associated with smoking. It is often broken down into stages that correspond to varying degrees of obstructed lung function. The exact stages can vary among the three main systems that are commonly used. These systems are known as the ATS (American Thoracic Society), GOLD (Global Initiative for Chronic Obstructive Lung Disease), and BODE index (body-mass index, airflow obstruction, dyspnea, and exercise capacity) systems.
There are four stages of emphysema in both the ATS and GOLD systems. In both of these systems, the stages are mild, moderate, severe, and very severe. All are characterized by progressively worsening lung obstruction, as determined by lung function testing. The GOLD system also incorporates a patient’s symptoms into each stage. For example, mild emphysema, which corresponds to slight limitation of lung airflow, may also include a chronic cough, according to the GOLD system.
The stages of emphysema range from zero to ten in the BODE index. These emphysema stages take into account a patient's body mass index, lung function, level of shortness of breath, and exercise ability. A score is given in each of these categories, with increasing scores corresponding to increasing severity of disease and decreasing life expectancy. For example, zero stage emphysema on the BODE index indicates that a person's condition is relatively mild and he or she has an 80 percent chance of surviving at least four years. At the other end of the spectrum, stage ten indicates a person's emphysema is very severe and that he or she has about an 18 percent chance of surviving for four years.
Patients with emphysema are often monitored for the stage of the disease that they are in. This is because assessing each stage can help determine what treatments are needed and show how a person's condition is progressing. For mild stage emphysema, lifestyle changes such as quitting smoking and avoiding air pollution are generally recommended. When a person moves to a higher stage, it usually indicates to health-care providers that lung damage is getting worse and that more aggressive treatment, such as the addition of medications, may be needed. For the most severe emphysema, surgery may be recommended to remove damaged lung tissue that is severely obstructing lung airflow.