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Explaining the COPD stages

Reviewed by: HU Medical Review Board | Last reviewed: July 2015.

Explaining the COPD stages

When people first receive a diagnosis of COPD, they take special breathing tests to find out which of the four stages of COPD that they currently have. Stage I is the mildest form of COPD, and patients move through Stages II, III, and IV if their condition continues to get worse. Most people find out that they have COPD during Stage I or II.

There is no way to cure COPD or undo the damage it does to the lungs. However, it is important to remember that if a person’s COPD is detected during the earlier stages, the right kind of treatment plan can slow down the rate at which the COPD progresses.

What is it like to live with Stage I – Mild COPD?1,2

Many people with Stage I – Mild COPD do not even know that they have COPD. This is because the symptoms can be very mild at this stage. For example, people may just think that they have a typical “smoker’s cough” that lasts for a couple of weeks or months, and produces more mucus than normal. But this cough may actually be an early warning sign of COPD. People with Stage I COPD have a small amount of blockage in the flow of air through their lungs, but not enough to really notice.

Because many people with Stage I COPD do not know that they have it, they do not receive treatment or make lifestyle changes like stopping smoking. This means that more symptoms may develop and get worse over time, such as:

  • Feeling short of breath during exercise or other physical activity
  • Feeling more tired during ordinary activities
  • More frequent coughing
  • Interrupted sleep

People with Stage I COPD have lungs that are working about 80% as well as completely healthy lungs.

What is it like to live with Stage II – Moderate COPD?1,3

Many people who receive a diagnosis of COPD already have Stage II – Moderate COPD. This is because the symptoms have usually gotten bad enough for the person to tell his or her healthcare provider about them. They have started to interfere with daily activities. In Stage II COPD, the amount of blockage in a person’s airflow has gotten worse than it was in Stage I.

The symptoms of Stage II COPD are similar to the symptoms of Stage I COPD that are listed above. However, the symptoms usually happen more often and might be more severe. Also, people with Stage II COPD may start to experience exacerbations (also called “flare-ups” or “attacks”) – a sudden attack of serious COPD symptoms.

People with Stage II COPD have lungs that are working between 50% and 80% as well as completely healthy lungs.

What is it like to live with Stage III – Severe COPD?1,4

A person with Stage III – Severe COPD has an airflow blockage that causes serious breathing problems. These problems can greatly affect the person’s quality of life. At this stage, a person might require a large number of medications and some people may need supplemental oxygen therapy.

Other symptoms that people with Stage III COPD experience are:

  • Severe shortness of breath
  • Difficulty with any kind of physical activity
  • Frequent exacerbations
  • Increased tiredness
  • Inability to sleep well due to breathing difficulties

People with Stage III COPD have lungs that are working between 30% and 50% as well as completely healthy lungs.

What is it like to live with Stage IV – Very Severe COPD?1,5

People living with Stage IV – Very Severe COPD experience the most severe symptoms of the disease, which can seriously affect their quality of life. Coughing becomes more frequent and it is more difficult to clear mucus from the lungs. Most people with Stage IV COPD need many types of medication and require oxygen therapy to make sure their bodies are receiving enough oxygen to function. Extreme tiredness and poor sleep are also common problems for people with Stage IV COPD.

In Stage IV COPD, exacerbations happen more often and can be severe enough to require regular hospital treatment. A patient may have problems with being underweight or overweight, or have trouble with the heart or circulatory system. Physical activity of any kind can be very difficult, but it is very important to stay as active as possible.

Stage IV COPD is sometimes called “end-stage” COPD. People with Stage IV COPD have lungs that are working less than 30% as well as completely healthy lungs.

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