Oxygen & RespiratoryFebruary 27, 2026·6 min read
By the CIRRUS Editorial Team — how we write and source this
COPD stages explained: the GOLD criteria in plain language
Your pulmonologist may reference a "GOLD stage." Here's what that grading system is actually measuring.
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades COPD severity primarily using FEV1 — the volume of air you can forcefully exhale in one second, measured by spirometry and compared to a predicted normal for your age, height, and sex.
Grade 1 (mild) is FEV1 at 80% of predicted or above, often with few noticed symptoms. Grade 2 (moderate) runs 50–79%. Grade 3 (severe) is 30–49%. Grade 4 (very severe) is below 30%, or below 50% with chronic respiratory failure. The grade alone doesn't dictate treatment — it's combined with symptom scores and exacerbation history.
That combined assessment is why two people with an identical FEV1 can be on different treatment plans: one with frequent flare-ups and significant breathlessness is managed more aggressively than one with the same spirometry number but stable, mild symptoms.
The number also isn't static in the short term — it can shift with an active infection or acute exacerbation, which is why staging is typically done when a patient is at a stable baseline, not during a flare.
This article is general health information, not medical advice, and doesn’t replace evaluation by your own physician. Talk to a doctor about anything specific to your own diagnosis or treatment.