The Four Stages of COPD

Chronic Obstructive Pulmonary Disease (COPD) is currently the third leading cause of death in the United States, preceded only by heart disease and cancer. It also encompasses two types of chronic lung diseases – emphysema and chronic bronchitis.

Healthcare officials have broken COPD into 4 stages: mild, moderate, severe and very severe. The stages are determined by tests administered by your doctor, such a spirometry tests and arterial blood gas tests. From these tests, your doctor will be able to tell you at which stage it has advanced to, and how it should be treated. The earlier it's caught, the easier it will be to treat it and hopefully stop it from progressing.

Stage I COPD – Mild

Most patients aren't diagnosed at this stage, because this stage is so subtle they don't even think to suspect that something is wrong. If you have a history of smoking, or if you've lived for many years with people who smoke heavily, you will need to keep a close eye on your lung health after the age of 40. Age and tobacco smoke put you at a high risk of developing COPD.

The things you need to watch out for is if you have a productive cough that goes on for much longer than a regular chest cold would. You might have gotten a cold, had a cough, gotten treated for it and the rest of the symptoms have gone away, but you still have that cough over a month later. You may have acquired your first exacerbation (COPD flare-up), which in a mild stage case, is just a chronic cough and excessive mucus production. If this is the case, you should get checked out and voice your concerns to your doctor. It's usually just treated with a prescribed short-acting bronchodilator.

COPD breakdown in the United States

Stage II COPD – Moderate

Your chronic cough would be worse at this stage, and you would be experiencing unusual shortness of breath after doing normal, everyday things, such as climbing stairs or while doing something mildly strenuous. This is the stage where it's more likely to be noticed and diagnosed. Your doctor might prescribe both long-acting and short-acting bronchodilators, as well as exercise and pulmonary rehabilitation to stop the advancement of the disease and regain some lung function.

Stage III COPD – Severe

You will find yourself becoming very tired, short of breath, and exacerbations are more common. You're much more susceptible to complications from the common cold, and getting the flu and pneumonia shot is required. You will most likely by prescribed bronchodilators, pulmonary rehab, and you might need to start using an oxygen concentrator to make sure you are getting enough oxygen throughout your body.

Stage IV COPD – Very Severe

Tasks as simple as eating become difficult during this stage of COPD. Your quality of life is much lower, and there is a very high risk for cardiovascular complications from the lack of oxygen in your body. Your doctor will most likely prescribe the use of oxygen therapy, as well as bronchodilators, corticosteroids, vaccines, and antibiotics to prevent any complications from lung infections and things like the flu.

23 Million Americans suffer from COPD

Have more questions about COPD?

Information on this page is for reference and educational purposes only. For more information about chronic obstructive pulmonary disease (COPD), talk to your doctor or primary care provider.

Page last updated: October 23, 2018


About Scott Ridl: Scott joined American Medical Sales and Rentals in 2008 as a Web Manager and Content Writer. He is a writer and designer. He is extensively trained on oxygen therapy products from leading manufacturers such as Inogen, Respironics, Chart, Invacare, ResMed and more. Scott works closely with respiratory therapists and oxygen specialists to educate the community about oxygen therapy products, COPD, asthma and lung diseases. He writes weekly columns and is passionate about educating the community on oxygen therapy and respiratory issues.

2 thoughts on “The Four Stages of COPD”

  • Curtis Watson
    Curtis Watson July 27, 2019 at 3:46 am

    Information was somewhat educational. However, signs/symptoms caused by COPD would have been even more educational. Although, you may have already written articles identifying health issues associated with COPD in addition to what is mentioned in this article.


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