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:
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 thatâ€™s less than 70% of FVC.
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 personâ€™s degree of airflow limitation or obstruction. The worse a personâ€™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:
|GOLD Stage I||Mild Emphysema||FEV1/FVC < 0.70||FEV1 â‰¥ 80% of normal|
|GOLD Stage II||Moderate Emphysema||FEV1/FVC < 0.70||FEV1 50-79% of normal|
|GOLD Stage III||Severe Emphysema||FEV1/FVC < 0.70||FEV1 30-49% of normal|
|GOLD Stage IV||Very Severe Emphysema||FEV1/FVC < 0.70||FEV1 < 30% of normal|
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:
According to WebMD, the GOLD staging system can be inaccurate when applied to individual people because it only considers a personâ€™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
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 isnâ€™t an exact science and emphysema symptoms vary widely between two people at the same stage, itâ€™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 personâ€™s prognosis.1
For more information about spirometry testing and emphysema, talk to your primary health care provider.
 WebMD. GOLD Criteria for COPD. Last reviewed November 26, 2015.
 Global Initiative for Chronic Obstructive Lung Disease. â€œGlobal Strategy for Diagnosis, Management and Prevention of COPD â€“ 2016. Updated December, 2015.
By Deborah LeaderÂ RN, BSN, PHN