Chronic Obstructive Pulmonary Disease (COPD) is typically categorized into four stages. Each stage represents a progressively worsening condition of the disease, with the airflow limitation increasing as the disease advances. The stages are generally defined based on the severity of symptoms, the impact on daily life, and the results of a lung function test known as the Forced Expiratory Volume in one second (FEV1). The FEV1 test measures how much air a person can expel from their lungs in one second, and the results are compared to what is expected for a person of the same age, gender, and size. Here is a brief overview of the stages: 1. Stage 1 (Mild): At this stage, the disease is often undiagnosed as symptoms are mild and may not be noticeable. The FEV1 is usually above 80% of the predicted value. 2. Stage 2 (Moderate): Symptoms become more apparent, and the FEV1 is between 50% and 80% of the predicted value. COPD starts to interfere with daily activities. 3. Stage 3 (Severe): The disease is more severe, with the FEV1 between 30% and 50% of the predicted value. Symptoms are more pronounced, and the impact on daily life is significant. 4. Stage 4 (Very Severe): This is the most advanced stage, where the FEV1 is less than 30% of the predicted value or when the patient has respiratory failure. The disease has a major impact on the patient's quality of life and survival. It's important to note that the staging of COPD can vary between healthcare providers and countries, and the FEV1 is just one aspect of the diagnostic process. read more >>

Stages (or grades) of COPD. COPD has four stages, and your airflow becomes more limited with each passing stage. Various organizations may define each stage differently. However, most of their classifications are based in part on a lung function test known as the FEV1 test.read more >>