What is Emphysema?
Emphysema is one of the major obstructive lung diseases that contribute to chronic obstructive pulmonary disease (COPD). It is the gradual destruction of the air sacs in the lungs, making it progressively more difficult to breathe. The tiny cluster-like air sacs in the lungs are responsible for bringing oxygen to the bloodstream. As emphysema progresses, the inner walls of the air sacs form holes weakening their internal structure. Thus, emphysema allows less oxygen to reach the bloodstream. Emphysema also destroys the elasticity of the airways leading to the air sacs.
As a result, the air sacs collapse trapping oxygen in the lungs. Sufferers of emphysema constantly feel short of breath and struggle to breathe. The lung damage from emphysema creates trapped air pockets, which prevent individuals from expelling air forcefully. The more air that is trapped, the worse lung function becomes, which makes breathing harder and pulmonary function test results decline.
How is The Severity of Emphysema Compared?
While emphysema is not typically construed as a four-step disease like its umbrella disease, COPD, there is still a major staging system available that can help practitioners and patients diagnose and understand their disease. GOLD (Global Initiative for Chronic Obstructive Lung Disease) put forth a set of criteria that helps divide emphysema cases into four progressive stages. To differentiate between the four stages, GOLD recommends monitoring the amount of air a person with emphysema can forcefully exhale in one second; this is called the forced expiratory volume or FEV1. The FEV1 is determined through a pulmonary function test administered by a pulmonologist. The possible results are divided into the severity of each stage of emphysema.
The Four Stages of Emphysema by GOLD
Stage 1: This is considered mild emphysema. The FEV1 must be greater than or equal to 80% of normal lung function.
Stage 2: As moderate emphysema, the FEV1 must be less than 80%, but greater than or equal to 50% of normal lung function.
Stage 3: Severe emphysema requires a FEV1 less than 50% of normal, but greater than or equal to 30%.
Stage 4: A FEV of less than 30% of normal, or of less than 50% or normal with low blood oxygen levels indicates very severe emphysema.
While the GOLD emphysema staging criteria is widely used by pulmonologists and physicians alike, it cannot be used to evaluate every person with emphysema as it fails to acknowledge how people with emphysema feel or their quality of life.