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Last Updated on February 7, 2023


Chronic obstructive pulmonary disease (COPD) is a long-term inflammatory lung condition characterized by a persistent cough and shortness of breath. While smoking is responsible for 85-90% of COPD cases, secondhand smoke, air pollution, and industrial dust and fumes all play a role. It is the third leading cause of death in the United States, affecting over 15 million people. COPD is staged from grade 1 to 4 based on the symptoms you experience and how well your lungs function. Let’s take a look at the COPD stages, the symptoms people experience on a daily basis, and COPD life expectancy.

About COPD

COPD is a progressive lung disease. It may begin with mild symptoms and then worsen. COPD makes it difficult to breathe. At first, symptoms may be mild, such as intermittent coughing and shortness of breath. As the disease progresses, symptoms can become more consistent, making it difficult to breathe, therefore gradually reducing COPD life expectancy.

You may experience wheezing, chest tightness, and excessive sputum production. Some people with COPD experience acute exacerbations, which are severe symptom flare-ups. Awareness and early detection of COPD, and COPD stages are important for slowing the disease’s progression and avoiding serious complications increasing COPD life expectancy.

What Causes COPD?

The most common cause of COPD is smoking. In fact, cigarette smoking is responsible for the majority of COPD cases. Breathing in someone else’s tobacco smoke repeatedly, especially as a child, increases your risk of developing COPD. Approximately 80 to 90% of COPD cases occur due to smoking or exposure to secondhand smoke. Exposure to air pollution, dust, and other chemicals can also increase your risk of COPD and decrease COPD life expectancy.

COPD can be caused by the genetic condition alpha-1-antitrypsin deficiency in very rare cases. This disorder is characterized by low levels of a protein that normally protects the lungs. Without this protection, lung tissue is damaged, potentially leading to COPD.

COPD Stages

There are various grading systems, one of which is part of the GOLD classification. GOLD is an abbreviation for “The Global Initiative for Chronic Obstructive Lung Disease.” The GOLD classification is used to determine the severity of COPD or COPD stages and to help form a prognosis and treatment plan.

COPD staging (or grading) has evolved significantly in recent years. And it’s quite complicated. The first thing to understand is determining how early or advanced COPD which is broken down into two components.

  1. The function of the lungs

On a spirometry breathing test, this is how “well” your lungs perform. It measures FEV1 or the amount of air you can blow out of your lungs in a 1-second burst after taking a full, deep breath.

Your FEV1 is compared to the FEV1 that is considered “normal” for someone your age, gender, height, and ancestry who has healthy lungs. Based on this, your COPD stages is assigned a GOLD stage ranging from 1 to 4.

  1. The Influence of Symptoms

Your COPD stages do not always correspond to how you feel. The second step in staging COPD is to consider how much and how frequently your symptoms affect you. ABCD groups are used to assess this (also from the GOLD organization). Your group is determined by the following factors:

  1. How much COPD symptoms affect you:

    The COPD Assessment Test is the best tool for assessing symptoms (CAT) and one’s COPD stages. This is an eight-question survey with a possible total score of 18. It inquires about the shortness of breath, but it also includes symptoms such as cough, mucus, sleep, and energy levels. Prior to the CAT, providers evaluated symptoms using the mMRC score, which only considered levels of breathlessness.

  2. How frequently you are ill with COPD:

    People with COPD frequently experience flare-ups or exacerbations. Knowing how frequently these occur and when they necessitate hospitalization can help you predict your future risk of exacerbations,  hospitalizations, and to an extent, COPD life expectancy. This is critical in determining which treatment is required to prevent this from happening.

What are the 4 Stages of COPD?

COPD stages are graded from 1 to 4, and a letter from A to D. These provide important information to the doctor about how to monitor and treat COPD. They’ll also be on the lookout for and treat any other illnesses a person has that may be affecting their COPD life expectancy. These are the 4 main COPD stages:

  • COPD grade 1: Mild
  • COPD grade 2: Moderate
  • COPD grade 3: Severe
  • COPD grade 4: Very severe

Further classifying COPD stages, it also contains a group letter:

  • Group A: You have 0 to 1 exacerbation per year, no hospitalizations, and a CAT score of less than 10.
  • Group B: You have 0 to 1 exacerbation per year, no hospitalizations, and a CAT score of 10 or higher.
  • Group C: You have two or more exacerbations per year, or you have been hospitalized, and your CAT score is less than ten.
  • Group D: You have 2 or more exacerbations or hospitalizations per year, and your CAT score is 10 or higher.

When healthcare providers consider lung function and the impact of symptoms altogether, they can get a sense of how COPD affects the lungs and you as a person. COPD stages or grading assists your care team in determining which treatment plan is best for you and how to cater specific treatments to your specific situation.

What is the Life Expectancy of COPD?

The progression of COPD differs greatly from person to person. Even if you have end-stage COPD, predicting your COPD life expectancy is difficult. That’s because there’s more to it than just how severe your COPD is or which of the COPD stages you might have.

The BODE index is a tool that healthcare providers can use to estimate COPD life expectancy in patients. It combines four components:
Body Mass Index (BMI): This is calculated using height and weight. Because people with COPD struggle to maintain their weight, a BMI greater than 21 is associated with a longer life expectancy.

Obstruction in airflow: This is determined by lung function.

Dyspnea: The mMRC questionnaire measures dyspnea, which is the medical term for shortness of breath.

Exercise capacity: It is the distance you can walk in 6 minutes.

By adding the scores for each element, the BODE score is calculated. The total score ranges between 0 and 10. The lower your COPD life expectancy, the higher your score.

While the BODE score can provide an estimate of COPD life expectancy, it is not a guarantee for you or your specific situation. This is due to the fact that the BODE index is based on statistics and provides averages for large groups of people. Furthermore, because the majority of the participants in the studies were men, experts are unsure how accurate the BODE index is for women.

Also Read: Is COPD Contagious?


Chronic obstructive pulmonary disease (COPD) is a progressive disease that worsens over time. While smoking is the leading cause, pollutants, secondhand smoke, dust, and fumes all play an equal role. Healthcare providers describe the severity of the disease using COPD stages, which will influence the treatment you receive. COPD does not have to limit your life expectancy even if you are in stage 4.

There is no cure for COPD. However the earlier COPD is diagnosed, the sooner treatment can begin, steps can be taken to slow its progression, and COPD life expectancy can potentially increase. Most patients with either of the COPD stages can achieve symptom control and lead a good quality of life.

Dr. Anusia Thourani

Dr. Anusia is a Dentist and currently working as a Recruitment Associate at Revive Research Institute. Her cheerful personality and enthusiasm for her work in this organization make her a great part of our team.

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