COPD SEVERITY SCALE

We've included this chart so that you will know what your doctor means when he or she tells you how severe your COPD is. Make sure to have your condition explained clearly to you, and find out everything you can about how to keep from progressing higher on this scale.

0: At Risk

This classification comes before major damage is really done. Your doctor has determined that you have the risk factors associated with developing COPD later in life, and he or she will probably recommend lifestyle changes and regular testing.

• Normal spirometry at every physician visit
• Symptoms (cough, sputum production) may be present, but not yet serious

I: Mild COPD

In this case, spirometry has shown mild airflow limitations due to chronic cough, mucus production, and the beginning of damage to your lungs. You may not be aware of your symptoms. Some characteristics of this stage include:

• FEV1/FVC < 70%
• FEV1 >= 80% predicted
• Starting to suffer from chronic symptoms (cough, sputum production)

II: Moderate COPD

At this stage, your airflow is getting worse. You have very noticeable symptoms, and dyspnea occurs with everyday exertion. This is when most people go to their doctor for the first time. Characteristics include:

• FEV1/FVC < 70%
• 50% <= FEV1 < 80% predicted
• Chronic symptoms (cough, sputum production)

III: Severe COPD

Very limited airflow. Dyspnea occurs after minimal exertion, to the point where even small tasks like leaving the house or going upstairs are a major issue. Characteristics include:

• FEV1/FVC < 70%
• 30% <= FEV1 < 50% predicted
• Chronic symptoms (cough, sputum production)

IV: Very Severe COPD

At this stage, complications such as respiratory failure and heart failure begin to develop. Quality of life is extremely impaired and the symptoms become life threatening. Characteristics include:

• FEV1/FVC < 70%
• FEV1/FVC <30% predicted or FEV1< 50% predicted plus chronic respiratory failure
• Classification based on post-bronchodilator FEV1
• Respiratory Failure: arterial partial pressure of oxygen PaO2 less than 60mmHg with or without PaCO2 greater than 50mmHg while breathing at sea level

FEV stands for Forced Expiratory Volume, or the amount of air you can blow out of your lungs in one second.

FVC stands for Forced Vital Capacity, or the total amount of air you can blow out.

FEV₁/FVC is the ratio that compares the amount you can blow out quickly to the total amount your lungs can blow out.

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