Stages of COPD

COPD is a common lung condition characterized by the persistent, abnormal decrease of airflow leaving the lungs. This airflow limitation is usually progressive, not fully reversible and does not change markedly over a period of several months.^[1] A breathing test known as spirometry is required to confirm a diagnosis of COPD. During a spirometry test, airflow limitation is measured and then classified according to its severity. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) there are four COPD stages (also referred to as grades) that range from mild to very severe. The lower your spirometry test score, the more severe your COPD.^[2]

In the past, a spirometry test was the only tool used to measure COPD severity. Recently, GOLD guidelines were updated to include COPD symptoms and COPD exacerbations (periods of time when COPD symptoms worsen) when measuring COPD severity. Combining symptoms and exacerbations with spirometry results give doctors a more accurate picture as to the true severity of COPD, which can better direct COPD treatment.²

Breakdown of COPD Stages

Spirometry measures forced vital capacity (FVC), the volume of air forcibly exhaled after taking the deepest breath possible and forced expiratory volume in one second (FEV₁), the volume of air exhaled during the first second of the test. It then calculates FEV₁/FVC, the ratio of these two measurements. The following chart demonstrates how these values are applied to COPD stages:²

GOLD I: Mild COPD

If you have GOLD I: Mild COPD, you have minor airflow limitation but you may not yet notice any COPD symptoms. Or, you may possibly have a cough with excess mucus production that you associate with smoking. Because people with GOLD I: Mild COPD rarely link COPD symptoms with lung disease, they usually don’t seek treatment at this stage.²

GOLD II: Moderate COPD

At this stage, your airflow limitation worsens and you may start to notice symptoms, particularly shortness of breath with increased activity along with cough and mucus production. Because symptoms start to become more problematic during GOLD II: Moderate COPD, it is at this stage that most people seek medical treatment.²

GOLD III: Severe COPD

During this stage, airflow limitation significantly worsens, shortness of breath becomes more evident and COPD exacerbations are more common. You may also start to notice that physical activity becomes more difficult and that you fatigue more easily than usual.²

GOLD IV: Very Severe COPD

At this level of COPD, your quality of life may be greatly impaired and COPD exacerbations may be life-threatening. Airflow limitation is severe and may start to affect your heart and other bodily systems leading to COPD complications such as cor pulmonale and respiratory failure.²

Keeping Your COPD from Getting Worse

It’s important to understand that the GOLD grading system is only meant to be used as a guideline; it’s not an exact science. What’s much more important is how you feel and how well you take care of yourself. There are some people living with GOLD IV: Very Severe COPD who take excellent care of themselves and lead a fairly normal life. On the other hand, there are those with GOLD II: Moderate COPD who are sedentary and continue to smoke who are dramatically affected by the disease.

To keep your COPD from worsening, consider the following steps:

• Quit smoking – smoking cessation is the single most important treatment measure to slow the progression of lung function decline in COPD. In fact, kicking the habit can actually normalize lung function decline, meaning it declines at the same rate as anyone else of the same age, sex, height and weight.^[3]
• Exercise regularly – participating in a regular exercise program will help you manage your weight, maintain your strength and help prevent the crippling effects of COPD.
• Maintain a healthy diet – eating a balanced diet is the best way to ensure you’re getting the right foods and the right amount of calories, an important, yet frequently overlooked aspect of COPD treatment.
• Avoid further exposure to airway irritants – continued exposure to airway irritants such as tobacco smoke, secondhand smoke, air pollution and workplace dust, fumes and harsh chemicals worsens lung function and can make your COPD progress at a faster rate.
• Comply with your COPD treatment plan – although there’s no cure for COPD, treatment can ease COPD symptoms, reduce the frequency and severity of COPD exacerbations and improve your quality of life.²
• Prevent COPD exacerbation – disease flare-ups contribute to a more rapid progression of lung function decline in COPD.^[4]
• Notify your doctor ASAP if symptoms worsen – calling your doctor at the first sign of a COPD exacerbation or another complication of COPD helps lesson their impact and greatly improves your chances of survival.

_{[1] Institute of Medicine (US) Committee on a National Surveillance System for Cardiovascular and Select Chronic Diseases. A Nationwide Framework for Surveillance of Cardiovascular and Chronic Lung Diseases. Washington (DC): National Academies Press (US); 2011. 3, Chronic Lung Disease. Available from: https://www.ncbi.nlm.nih.gov/books/NBK83163/.}

_{[2] From the Global Strategy for the Diagnosis, Management and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017. Available from: http://goldcopd.org.}

_{[3] David M. Mannino, Matthew M. Reichert and Kourtney J. Davis. Lung Function Decline and Outcomes in an Adult Population. The Am. J. Respir. Crit. Care Med., Vol 173. pp. 985-990, (2006).}

_{[4] A. Anzueto. Impact of exacerbations on COPD. European Respiratory Review Jun 2010, 19 (116) 113-118; DOI: 10.1183/09059180.00002610.}