COPD is largely underdiagnosed in the U.S. But it’s important to know if you or a loved one has the disease. The sooner the diagnosis is made, the sooner treatment can begin. Although there is no cure for COPD, treatment can slow the disease and improve your quality of life. If you are diagnosed with COPD, your doctor will work with you to determine the severity of your condition. This can be a complex process, because COPD affects everyone differently. The purpose of assessing severity is to identify your risk of hospitalization and other serious complications and to understand what type of treatment is best. The Complexities of Assessment The guidelines for assessing disease severity have changed over the last several years. The Global Initiative for Chronic Obstructive Lung Disease (GOLD), the organization that sets the guidelines, used to stage the disease primarily based on spirometry testing. Spirometry tests measure airflow limitations. Based on their readings, patients were given a disease stage. At the time, experts believed that a person's symptoms, such as breathlessness, largely followed the same progressive path. Today, experts know that response to COPD can vary from person to person. Spirometry testing remains the primary tool for diagnosing COPD and is also used to help assess severity of disease. However, overall severity is now based on other factors as well, including the person’s symptoms and health status. Some tools used to evaluate these factors include the COPD Assessment Test (CAT), which is a standard questionnaire used to assess health status, and the Modified British Medical Research Council (mMRC) questionnaire, which is used to measure disability due to breathlessness. Determining Your Severity Based on a comprehensive assessment of many factors, patients are grouped into different levels of severity. Using the GOLD groupings listed below, your doctor will know how to best target your treatment based on your individual needs: Group A: Low Risk, Fewer Symptoms Typically has mild to moderate airflow limitations 0–1 exacerbation per year mMRC grade 0–1 or a CAT score of less than 10 Group B: Low Risk, More Symptoms Typically has mild to moderate airflow limitations 0–1 exacerbation per year mMRC grade 2 or higher or a CAT score of 10 or more Group C: High Risk, Fewer Symptoms Typically has severe or very severe airflow limitations 2 or more exacerbations per year mMRC grade 0–1 or higher, or CAT score of less than 10 Group D: High Risk, More Symptoms Typically has severe or very severe airflow limitations 2 or more exacerbations per year mMRC grade 2 or higher, or a CAT score of 10 or more Key Takeaways The purpose of assessing the severity of COPD is to identify your risk for serious complications and to determine the best type of treatment. Severity is based on spirometry testing and factors such as your symptoms and health status. Patients are grouped into four levels of severity, based on their symptoms and risk level.