Chronic obstructive pulmonary disease affects a person's lungs and their ability to breathe. The most common cause is smoking.
Chronic obstructive pulmonary disease (COPD) is a progressive condition in which it becomes increasingly difficult for the lungs to function efficiently. The lung tissue thickens and becomes less elastic, and the lungs produce more mucus.
Health professionals often use four stages to classify COPD according to how well the lungs are working. The most severe phase is end-stage COPD. At this stage, it becomes challenging to carry out regular activities and daily functions.
According to the American Lung Association, COPD is the third most common cause of death in the United States.
There is no cure for COPD, but medications and lifestyle changes can help reduce symptoms and slow down the progression of the disease.
Doctors use stages ranging from one to four to classify COPD, depending on the severity of symptoms and the frequency of exacerbations, or flares.
End-stage COPD is the most severe stage. A person with end-stage COPD will experience more symptoms overall and have a high risk of acute exacerbations of their chronic breathing difficulties.
Doctors will often use breathing tests to make spirometric classifications and determine which stage of the disease a person has reached.
Spirometry measures a person's lung function. The individual blows into a handheld device that records how much air they can blow in and out.
A person with COPD is usually unable to take in or blow out as much air as a person with healthy lungs.
Therefore, the measurements can help determine the severity of the person's COPD.
The measurements include:
FEV1: This stands for forced expired volume in one second. The test measures how quickly a person can empty the air from their lungs.
FVC: Forced vital capacity refers to the maximum amount of air that a person can blow out when they are trying to exhale all the air that they possibly can.
FEV1/FVC: This compares the two measurements above. The result indicates how severe COPD has become. A healthy adult will have a ratio of between 70 and 80 percent. A ratio below 70 percent generally indicates COPD.
These spirometry measurements help doctors determine how to classify a person's COPD. There are different ways of staging COPD, but one system that doctors often use is the GOLD criteria.
This takes its name from the Global Initiative for Chronic Obstructive Lung Disease (GOLD) who created it.
Initially, these stages were based only on the FEV1 result. However, the GOLD committee felt that using this one measurement was insufficient for estimating the severity of the disease.
In 2018, the health authorities published a new revision of the criteria for the test to also take a person's symptoms into account.
In addition to taking spirometry measurements, doctors will now ask a series of questions using either the COPD Assessment Test (CAT) or the modified Medical Research Council (mMRC) dyspnea scale.
These tests ask questions about breathing during daily activities and give a numerical score based on the answers.
For example, in a CAT test the respondent will use a scale of 1 to 5 to explain how often they cough, the extent to which their condition affects activities at home, how well they sleep, and so on. The test has eight questions.
The score provides an idea of how much impact COPD has on a person's life. The more significant the impact, the more intervention the person will need.
The COPD classifications have changed to take this score into account, as well as the number of exacerbations that a person has experienced. The classifications are summarized below:
Group A: Low risk, fewer symptoms
The following criteria will apply to the people in group A:
Lung function: FEV1 tests will show that breathing capacity is less than 80 percent of normal (previously known as GOLD 1 stage) or between 50 and 79 percent of normal (formerly GOLD 2).
Exacerbations: The person will have either no exacerbations or only one per year, and they will never have spent time in the hospital for a COPD exacerbation.
Test scores: The CAT score will be less than 10 or the mMRC score will be 0 to 1.
Group B: Low risk, more symptoms
In group B, an individual will have the same FEV1 values as those in Group A.
They will also have no exacerbations or just one per year and no previous hospitalizations for COPD exacerbations.
However, they will have more symptoms and will frequently become short of breath when active. Symptoms may be starting to interfere with daily life, and the person will usually have seen a doctor about their breathing.
This will lead to a CAT score of 10 or more or an mMRC score of at least 2.
Group C: High risk, fewer symptoms
Lung function tests will show an FEV1 between 30 and 49 percent of normal (formerly GOLD 3) or less than 30 percent of normal (GOLD 4).
The person will have two or more exacerbations each year and have been hospitalized at least once for a breathing-related issue.
People in this group will have fewer symptoms. They will have a CAT score of less than 10 or an mMRC score of 0 to 1.
Group D: High risk, more symptoms
Individuals in Group D:
- have a very high risk of exacerbations
- have lung function test results that are similar to those in Group C
- have two or more exacerbations per year
- have been hospitalized at least once for a breathing-related issue
These individuals experience more symptoms than those in Group C, and they have a CAT score of 10 or above or an mMRC score of 2 or more.
A person with end-stage COPD is likely to have symptoms that are similar to those at other stages, but more frequent and severe. The person is more likely to need medical care.
Typical symptoms include:
- a chronic cough
- difficulty finishing a meal due to shortness of breath
- sudden, acute exacerbations or worsening of the condition
- frequent phlegm production
- low blood oxygen levels if the person is not using additional oxygen
- need for oxygen on a regular basis
- shortness of breath, even with very moderate activity
- confusion, due to low oxygen levels
In addition, the National Heart, Lung, and Blood Institute (NHLBI) note that people in the later stages may experience:
- swelling in the arms, legs, or feet
- weight loss
- loss of muscle strength
- difficulty breathing or talking
- a blue or gray tinge to the lips and nail beds
- loss of mental alertness
- rapid heartbeat
The treatment strategies that usually help often lose effectiveness when the disease reaches this stage.
Therefore, it is essential that people with this condition adopt behaviors that reduce the likelihood of the disease progressing to end-stage COPD.
COPD is a long-term and progressive condition. Treatment may not stop the disease from progressing, but it can relieve symptoms and make the condition more manageable.
Complications include hypoxia when at rest, which means that oxygen saturation is too low to breathe effectively.
Other problems include vulnerability to infections, acute exacerbations, and confusion. The complications can be life-threatening.
There is no cure for COPD, but there are ways of managing the symptoms.
According to the World Health Organization (WHO), these include the use of:
- bronchodilators, specifically beta-2 agonists, anticholinergics, theophylline, or a combination of these, available for long- and short-acting effects, to inhale or to take by mouth
- inhaled glucocorticosteroids for people with severe symptoms
- supplemental oxygen, which the person may need for several hours each day
As the disease progresses, the person may require hospitalization so that they can have assisted breathing and intubation.
Treatment cannot cure COPD, but it can prevent it from getting worse.
Living with end-stage COPD
A person with end-stage COPD should take precautions to prevent their symptoms from worsening. Each exacerbation can damage the lungs further, and this will slow down recovery.
The Centers for Disease Control and Prevention (CDC) suggest doing the following to reduce the risk of exacerbations:
Avoiding exposure to secondhand smoke by not being around people who are smoking, not allowing others to smoke in the home, and not wearing clothes that smell of smoke.
Quitting smoking, if applicable.
Checking the air quality outdoors every day and staying in when there is a lot of smog or a high pollen count.
Having vaccinations against pneumonia and flu to prevent infections that could worsen the condition of the lungs. It is vital to seek immediate treatment if there are signs and symptoms of infection, such as yellow- or green-tinged sputum.
Following the doctor's instructions, including those regarding prescribed medications, such as bronchodilators to keep the airways as open as possible, corticosteroids to reduce inflammation, and oxygen therapy.
There is no cure for COPD, and the outlook for a person with end-stage COPD is poor.
A ventilator can aid breathing, but it cannot repair damaged lungs that can no longer take in enough oxygen to sustain life.
A severe infection, such as pneumonia, may leave the lungs unable to recover. The individual may also experience very high levels of carbon dioxide in their body.
This can cause a person to experience confusion and delirium, and it can result in the blood becoming acidic, which can be dangerous.
A person with end-stage COPD should ask their doctor about their life expectancy, as this will depend on a range of individual factors.
COPD is a disease of the lungs.
The lungs resemble two tree trunks with many branches coming off them. These branches divide into smaller ones that have air sacs at their ends.
In these sacs, the exchange of oxygen and carbon dioxide takes place. Carbon dioxide is a waste product that people breathe out.
Healthy air sacs are stretchy, and they work in a way that is similar to blowing up a balloon and then releasing the air from it.
COPD can affect air exchange in the following ways:
- The air sacs lose their stretchiness, which affects their ability to open and close.
- The branches of the lungs become thickened, scarred, and inflamed.
- The airways secrete more mucus. This mucus clogs the air sacs, making it difficult for them to open and close. This, in turn, makes breathing more challenging.
Emphysema damages the air sacs. It can destroy smaller air sacs and make larger air sacs less elastic so they do not work as well as before.
Chronic bronchitis causes excess mucus to build up and makes the airways thicker.
Smoking is responsible for up to 75 percent of COPD cases, according to the NHLBI. Other causes include exposure to lung irritants, such as air pollution. More rarely, the disease may result from a genetic condition.