Let's Talk About COPD Stages

Not all cases of this lung disease are equal. Learn more about the grading system for COPD, and what it means for your health outcomes.

by Marjorie Korn Health Writer

Chronic obstructive pulmonary disease, or COPD, doesn’t get the kind of attention it should, given that it’s the fourth leading cause of death in the U.S. and those who have it are stuck with it for life. Still, despite its seriousness, the disease can be managed with the right course of treatment. By sizing up your COPD stage or grade, your medical team can figure out how far the disease has progressed, the way it's impacting how you feel, and what treatments will work best. When your doctors talk to you about staging or grading, this is what they mean.

COPD Stages

Our Pro Panel

We went to some of the nation's top experts in COPD to bring you the most up-to-date information possible.

Nereida A. Parada, M.D. headshot.

Nereida A. Parada, M.D.

Associate Professor of Medicine, Clinical Lead for Asthma and COPD

Tulane School of Medicine, Tulane Asthma Center

New Orleans, LA

Paul Andrew Reyfman, M.D. headshot.

Paul Andrew Reyfman, M.D.

Assistant Professor of Medicine, Pulmonary and Critical Care

Northwestern University Feinberg School of Medicine

Chicago, IL

Byron Thomashow, M.D.  headshot.

Byron Thomashow, M.D.

Professor of Medicine, Co-Founder and Senior Medical Advisor

Columbia University, COPD Foundation

New York, NY

COPD Stages
Frequently Asked Questions
Does a spirometry test hurt?

Not it all, and it takes less than 15 minutes. If you’ve ever practiced breathing in yoga class or meditation, it’s easy to get in the groove of the breathing that’s being asked of you. (There are studies in the works to confirm that a Peak Flow Test, a simpler set-up used to monitor people with asthma, is accurate and useful, too.)

Is grading COPD like cancer staging?

No. For cancer, staging is indicative of how widespread the disease has become. When cancer organizations update staging information, it’s because they’ve learned more about things like the way a tumor progresses, and the therapies that could stop its spread. In the case of COPD, grading is more a reflection on how a patient feels.

Why did the COPD staging system change?

Until a few years ago, most physicians used a 1-4 scale to stage COPD. But they found it didn’t accurately capture how someone felt, or predict the likelihood of flares or other COPD complications, so they switched to a letter-based approach that measured a person’s experience with COPD as well as lung function.

Where can I find other people with COPD?

The COPD Foundation created a community called COPD360Social where you can talk to people going through the same thing as you, get educational material, monthly newsletters, and more. Visit COPDFoundation.org to sign up.

Remind Me, What Is COPD?

The big hint for understanding chronic obstructive pulmonary disease (COPD) comes from the “pulmonary” part of the name, meaning that the action takes place in the lungs. And in fact, one of the biggest signs of this condition is shortness of breath caused by damage in the lungs, which makes it feel like you’re not able to get enough oxygen. You breathe harder and faster, but never feel like you can get enough air.

COPD is a widespread problem, both in the U.S.—where 16.4 million people have been diagnosed—and around the world, where as many as 250 million people do battle with the disease every day. So if your doctor suspects you have this chronic condition, or if you or a loved one has just been diagnosed, know that there are a lot of people in the same boat.

COPD is often referred to in stages. But before we get into how the staging works, it’s helpful to understand the makeup of the lungs. Yes, you know they are like balloons that inflate and deflate as you breathe. But the air doesn’t enter a cavern. Instead, the lungs are made up of multiple parts, each of which works in harmony with the others to deliver oxygen to the rest of your body, which is critical for survival. Here’s a quick rundown on how it all works:

  • When you inhale, air is sucked through your nose and mouth, passes through the larynx, then down into the trachea (or windpipe). The trachea is the direct passageway into the lungs.

  • The air first gets divided into the left and right primary bronchi—the tubes of the lungs. Like the branches and twigs on a tree, the bronchi keep splitting off and getting smaller until they reach the end of the line.

  • What’s at the end of the line? Your alveoli—collections of tiny air sacs that are clustered together like grapes on a vine. A healthy set of lungs boasts about 480 million of these alveoli.

  • To understand alveoli, think about a balloon. Blow into it and it expands. Suck the air out and it shrinks. The magic of the alveoli is that they separate out the oxygen from the air that you’ve inhaled, and feed it to your bloodstream via capillaries in order to fuel your muscles and tissues.

  • The alveoli have a second function: releasing carbon dioxide. The capillaries collect and expel carbon dioxide, so that when you exhale, the CO2 passes through all those alveoli, back through the trachea and larynx, and out your nose and mouth. It’s a process called gas exchange.

That how it works in theory, anyway. But sometimes environmental factors and even genetics can mess with that process. This can happen in a couple of different ways, as COPD is an umbrella term that incorporates a few different breathing-related conditions. Emphysema and chronic bronchitis are two of the most typical diagnoses. Let’s review what happen with these disorders.


In this disease, the walls of the alveoli break down and the number of tiny, individual air sacs decreases, leaving you with just a few, larger sacs. That means there’s less surface area to filter out the oxygen, hence the feeling like each breath isn’t satisfying enough. And then there’s damage to the airway themselves, making them less pliable, leaving you feeling short of breath.

Chronic Bronchitis

Bronchial tubes that become inflamed and irritated can end up being bronchitis. Coughing fits and shortness of breath are high on the list of symptoms, and if they last long enough or keep recurring (producing mucus at least three months at a time for two years in a row), it’s considered chronic bronchitis, a form of COPD. Your doctor is definitely able to help treat it, but not fully cure it.

Get the Full Story on COPD

What Are COPD Risk Factors?

People who are diagnosed with COPD share at least one of a few similarities. These are some of the common contributors to the disease.

  • You’re at least age 40

  • You are currently a smoker or used to be; you live in a house with someone who smokes

  • You’re frequently exposed to chemicals or pollution, usually because of an occupation

  • You cook over an open flame, thus getting exposed to biomass fuels

  • You have a relative who has been diagnosed with COPD

Two other factors play a role: Gender and genetics.

Gender: Women are more likely to be diagnosed with COPD—and there are a few theories as to why. It could be the result of a big push in the 1960s by tobacco companies to convert women into smokers. Also, we know that women’s immune response is different than men’s, which could play a role. Finally, women may be quicker to go to the doctor when they’re feeling like something’s amiss, meaning that there are more men out there who are undiagnosed.

Genetics: For a fraction of patients, there’s a genetic predisposition to COPD, and emerging research from Columbia University Medical Center suggests that some people may have lung “architecture” that predisposes them to the condition.

What Are COPD Symptoms?

These signs of COPD seem pretty vague and ordinary—almost like they could be describing asthma or run-of-the-mill allergies. (To make things more dicey, both asthma and allergies can contribute to the development of COPD.) The best way to look at the symptoms is in terms of the chronic component: The longer they linger, the more concerned you should be. Here’s the rundown of symptoms to keep an eye on:

  • Coughing: Includes wet (producing mucus) or dry coughs.

  • Low energy: Lack of oxygen induces fatigue.

  • Recurring respiratory infections: COPD makes it hard to clear lungs of bacteria, dust, and other pollutants.

  • Shortness of breath: During exercise or other activities.

  • Tightness in the chest: It feels as if there’s nowhere for the air to go.

  • Unintended weight loss: Your body has to work harder for oxygen, burning more calories.

  • Wheezing: May occur on either your inhale or exhale.

  • Exacerbations: Period of symptoms getting worse for a few days at a time.

How Is COPD Staged?

In order to figure out how far along your COPD has progressed, your doctor will want to run a series of tests that evaluate the severity of this chronic condition. This is done in several ways:

Spirometry: During this common lung function test that can be done in-office, you’ll be asked to put your lips around a mouthpiece and follow instructions for inhaling and exhaling. You will be evaluated on things like the degree of force your lungs produce when you blow out air.

Arterial blood gas analysis: This blood test measures how efficiently your lungs are carrying oxygen into your blood and removing carbon dioxide.

Chest x-ray: This text can show emphysema and also rule out other lung problems or heart failure.

CT scan: A more precise look at your lungs compared to an x-ray, this test can also help detect emphysema and be used to screen for lung cancer.

Using the results of these tests, plus questionnaires and a patient history, your doctor will come to a conclusion about the stage of COPD you have.

If you’ve had COPD for a few years now, you probably talked with your pulmonologist at some point about the Global Initiative for Chronic Obstructive Lung Disease (GOLD) COPD Stages. For years, this was the (literally) gold standard in evaluating the severity of someone’s COPD. It uses a 1-4 ranking system, with one being mildest amount of obstruction and four being the most severe.

The numbers are based on a person’s FEV1 score, which stands for forced expiratory volume in one second—one of the data points you get during a spirometry test. (Human translation: The strength of your exhale.) As a person’s COPD gets worse, the numbers go up and your GOLD COPD Stage does, too.

Recently, though, the GOLD Foundation has begun shifting away from that staging system to one that uses a letter grade. The reason: It’s a little more refined, since lung function doesn’t necessarily correlate with how you actually feel with COPD. (Sometimes, your lungs might show poor functioning even though you feel like you’re getting a reasonably amount of oxygen, or vice-versa.) Also, the old system wasn’t great at predicting the outcomes that doctors worry about (namely flares, progression of COPD, and death).

The updated categorization system looks like this:

  • A: less symptoms, low risk

  • B: more symptoms, low risk

  • C: less symptoms, high risk

  • D: more symptoms, high risk

A physician arrives at an individual’s grade based on a few different numbers, including:

  • How many times you have had a flare or been hospitalized.

  • How you rate on the Modified MRC Dyspnea Scale (mMRC), a grading of how quickly a person becomes breathless with activity.

  • What your CAT Assessment score is, which rates a patient’s experience on things like chest tightness and phlegm in the lungs.

Doctors use these grades to help them in their thinking about which medication or combination of medications they should consider as they treat an individual’s COPD. Pulmonologists will check in with their patients to see if their letter category changed between appointments.

Understanding Your COPD Stage

Don’t get too hung up on your grade for this condition. The outcome is helpful to a doc in terms of considering treatments, but it’s far from the whole story. Treating COPD is not necessarily straightforward. Comorbidities are common—meaning more than one disease is at play at the same time. For example, it’s common to have COPD as well as asthma or allergies. Just as important as the diagnostic test is a really detailed medical history. Armed with all of that knowledge, your pulmonologist will want to make a game plan that takes into account the findings of other doctors on your “team” as well, such as cardiologists, endocrinologists, and psychiatrists.

Because COPD develops over time based on the cumulative effects of environmental factors (read: decades of smoking cigarettes), symptoms often don’t appear until you are in your 40s or 50s. But a doctor who asks the right questions to younger adults may be able to spot risk factors (like smoking status) and detect chronic obstruction early on—rather than let it go untreated until your COPD stage has progressed to a C or D level.

Regardless of when you are diagnosed, the important thing to know is that you have treatment options. Whatever your grade is, there are medications, breathing aids, and lifestyle changes you can make that will help you manage the condition. But in order for these things to work in your favor, you need to go to all your pulmonology appointments, follow the treatment plan your doc prescribes, and commit to living a healthy life. Is it a walk in the park? Not really. But then, neither is COPD. A journey of a thousand miles begins with a single step (or whatever that ancient Chinese proverb says). Go on, now. You can do this.

Marjorie Korn
Meet Our Writer
Marjorie Korn

Marjorie Korn is a health, medicine, and features writer based in New York City. She is also a Narrative Medicine instructor at Columbia University College of Physicians & Surgeons.