The 4 stages of Chronic Obstructive Pulmonary Disease (COPD) are generally classified based on the severity of airflow limitation measured by lung function tests, particularly the forced expiratory volume in one second (FEV1). The stages are:
- Stage 1: Mild COPD
- FEV1 is 80% or more of the predicted value.
- Symptoms may be mild or absent.
- Mild shortness of breath and chronic cough may occur.
- Stage 2: Moderate COPD
- FEV1 is between 50% and 79% of the predicted value.
- Symptoms become more noticeable with increased breathlessness during physical activity.
- More frequent coughing and mucus production may happen.
- Stage 3: Severe COPD
- FEV1 is between 30% and 49% of the predicted value.
- Symptoms worsen, with increased shortness of breath even during less strenuous activities.
- Daily activities may start to become difficult, and flare-ups become more frequent.
- Stage 4: Very Severe COPD
- FEV1 is less than 30% of the predicted value.
- Severe symptoms are present even at rest.
- There is a risk of complications like respiratory failure or heart problems.
- Oxygen levels in the blood may be low, and lung function is severely impaired.
These stages help guide treatment options and management plans to improve quality of life and slow disease progression. Treatments vary by stage but can include smoking cessation, bronchodilators, pulmonary rehabilitation, oxygen therapy, and in advanced stages, surgery like lung transplants.
