Emphysema Stages

Emphysema is among a group of lung diseases classified as chronic obstructive pulmonary disease, or COPD. A simple breathing test called spirometry is used to diagnose emphysema and determine its severity. Spirometry measures the amount of air entering and leaving the lungs. Two important values that are measured during a spirometry test are:

• Forced expiratory volume in one second (FEV₁) – the volume of air, measured in liters, in a one second, forced exhalation
• Forced vital capacity (FVC) – the total volume of air exhaled, measured in liters

In people with normal lung function, FEV₁ is at least 70% of FVC. People with emphysema who have difficulty blowing out all their air when they breathe typically have an FEV₁ that’s less than 70% of FVC.^[1]

Classification of Severity of Airflow Limitation in Emphysema

The Global Initiative for Chronic Obstructive Lung Disease (GOLD), a collaboration between the National Institutes of Health and the World Health Organization, classifies the severity of COPD based on a person’s degree of airflow limitation or obstruction. The worse a person’s airflow limitation, the lower their FEV₁. As emphysema progresses, FEV₁ tends to decline.¹

GOLD staging, as we see below, uses four categories of severity for COPD, based on the value of FEV₁:^[2]

Understanding the GOLD Stages of Emphysema

Classifying the severity of emphysema according to stages helps people with COPD understand their disease better and helps doctors make better treatment recommendations for their patients.¹ The following offers a general understanding of what to expect during each stage of emphysema:

• GOLD Stage I: Mild Emphysema – people with mild emphysema are usually not aware that their lung function has started to decline. Emphysema symptoms may not yet be noticeable and if they are, they’re usually not attributed to lung function decline or the disease process.
• GOLD Stage II: Moderate Emphysema – at this stage, airflow limitation begins to worsen and symptoms may start to become noticeable, particularly shortness of breath with activity along with cough and mucus production.
• GOLD Stage III: Severe Emphysema – as the disease progresses to this stage, airflow limitation significantly worsens, shortness of breath becomes more evident and COPD exacerbations are more common. There may also be a decrease in activity tolerance and an increase in fatigue.
• GOLD Stage IV: Very Severe Emphysema – once the disease reaches GOLD Stage IV, quality of life may be greatly impaired and COPD exacerbations may be life threatening. Airflow limitation is severe and shortness of breath may occur even while at rest.

Limitations of the GOLD Staging System

According to WebMD, the GOLD staging system can be inaccurate when applied to individual people because it only considers a person’s degree of airflow obstruction. While in general, people with severe or very severe airflow obstruction have worse symptoms and a shorter life expectancy than people with mild or moderate obstruction, there are a host of other factors that influence symptoms and life expectancy as well, such as:¹

• Obesity
• Smoking status
• Other medical conditions, especially heart disease
• Physical fitness and exercise habits

This means, for example, that a person with severe emphysema who performs daily exercise may experience fewer symptoms and live longer than a person with mild emphysema who is in poor physical condition.¹

Because emphysema staging isn’t an exact science and emphysema symptoms vary widely between two people at the same stage, it’s impossible to accurately predict life expectancy in any one individual. That said, the most important determinant of emphysema life expectancy is whether a person with emphysema continues to smoke. Quitting smoking is the single most effective way to slow the progression of lung function decline that occurs in emphysema and improve a person’s prognosis.¹

For more information about spirometry testing and emphysema, talk to your primary health care provider.

_{[1] WebMD. GOLD Criteria for COPD. Last reviewed November 26, 2015.}

_{[2] Global Initiative for Chronic Obstructive Lung Disease. “Global Strategy for Diagnosis, Management and Prevention of COPD – 2016. Updated December, 2015.}

By Deborah Leader RN, BSN, PHN