Chronic obstructive pulmonary disease (COPD) is a group of diseases, most commonly emphysema and chronic bronchitis. COPD is a disease that may gradually get worse and move through different stages from mild to very severe. There is no cure for COPD even at early stages. Although COPD is a lifelong disease, early diagnosis and treatment can improve quality of life and life expectancy. [1-5]
Stages of COPD have been used to predict survival in the past, but doctors have learned that survival depends on many factors. [1,4,5] Improved treatment for COPD is now available even for advanced stages. Treatment can control symptoms, slow progression, and allow people to live longer more active lives at any stage. [2,3,5]
The Four Stages of COPD
Stages of COPD used to be based on lung tests like spirometry and other pulmonary function tests. These tests measure your lung capacity. According to the COPD Foundation, pulmonary function testing is no longer considered a one-size-fits all way to stage or predict COPD.  Lung function tests alone can’t predict how COPD will progress over time. [1,4]
Other things that affect the stage and progression of COPD include your genes, your body weight, how short of breath you get with activities, even how far you can walk in six minutes. Other diseases you live with may also have a big impact on survival. These include diseases like heart disease, diabetes, depression, and anxiety. [1,4]
The COPD Foundation describes the stages as a guide to help you and your doctor find the best treatment, not as a way to predict survival.  These are the stages and their symptoms: 
Stage 1, Mild COPD
Symptoms of stage 1 COPD include a persistent cough and shortness of breath on exertion. The coughing could bring up mucus, or just be dry. This is when lung damage begins, but can easily be missed because the symptoms remain mild.
Stage 2, Moderate COPD
Symptoms of stage 2 COPD include cough and shortness of breath, which may occur during routine activity. The cough may be worse in the morning and bring up more mucus. These coughing fits and discomfort can begin to disturb sleep and cause daily fatigue.
Stage 3, Severe COPD
As stage 3 COPD sets in, stage 2 symptoms will worsen along with frequent upper respiratory infections, tightness in the chest, and difficulty getting a deep breath. Daily life begins to change, as this disease impacts the quality of life. In addition to the lung symptoms, swelling of feet, ankles, and legs may occur.
Stage 4, Very Severe COPD
In stage 4, all of the COPD symptoms will continue to worsen along with constant wheezing, loss of weight, and loss of appetite. Increased heart rate and blood pressure, delirium, and a barrel-shaped chest also occur.
Treatments Prolong Life and Improve Quality of Life
For stage I COPD, the most effective treatment and the best way to prolong survival is to stop smoking. Without this step, no other treatments can prevent COPD from getting worse.  There are many medication options for all stages of COPD. Examples include inhalers that open your lungs and decrease inflammation, oral medications that improve breathing, and antibiotics to fight off infections. [2,3,5]
Other therapies include oxygen, pulmonary rehabilitation programs, and surgery. Oxygen therapy along, with not smoking, definitely improves survival.  Pulmonary rehab programs include education, exercise, nutrition advice, breathing exercises, and counseling. Surgical advances for COPD include procedures that remove damaged lung tissue to make room for healthy lung tissue, called lung volume reduction. A lung transplant is now an option for some people. [2,3,5]
Lifestyle Changes for Living Better with COPD
You will learn breathing techniques and breathing exercises to help you breathe better in pulmonary rehab. You can use these regularly at home. Other ways to manage COPD at home include: [2,3,5]
- Controlled coughing to clear mucous
- Drinking plenty of fluids
- Avoiding secondhand smoke and air pollution
- Staying as fit as you can with physical activity and exercise
- Eating a balanced diet with enough calories to maintain your weight
- Getting your vaccinations
COPD is a serious disease and it does tend to get worse over time. Although there is no cure, COPD can be treated. Stages of COPD are important for choosing the best therapies, but the stage of COPD is not the last word on survival. With advanced treatment and lifestyle changes any stage of COPD can be treated.
- COPD Foundation, Stages of COPD, https://www.copdfoundation.org/Learn-More/I-am-a-Person-with-COPD/Stages-of-COPD.aspx
- Mayo Clinic, COPD, https://www.mayoclinic.org/diseases-conditions/copd/symptoms-causes/syc-20353679
- NYU Langone Health, COPD, https://nyulangone.org/conditions/chronic-obstructive-pulmonary-disease-in-adults/support
- BMJ Best Practice, COPD, Prognosis, https://bestpractice.bmj.com/topics/en-us/7/prognosis
- MedicineNet, What is COPD? https://www.medicinenet.com/what_are_the_four_stages_of_copd/article.htm