Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a long-term lung condition that makes it progressively harder to breathe. It occurs when the airways and lung tissue become damaged, leading to reduced airflow and less efficient oxygen exchange in the lungs. COPD develops gradually over time, and while it cannot currently be cured, treatments and lifestyle changes can help control symptoms and slow disease progression. Early diagnosis and treatment are recommended.

The condition includes two related lung problems: chronic bronchitis and emphysema. Chronic bronchitis involves ongoing inflammation of the airways, causing excess mucus production, coughing, and chest discomfort. Emphysema involves damage to the small air sacs in the lungs, which reduces the lungs' ability to transfer oxygen into the bloodstream. Many people with COPD experience shortness of breath, persistent cough, wheezing, and reduced exercise tolerance.

COPD can develop due to multiple factors, most often involving long-term exposure to lung irritants. The strongest risk factors are tobacco smoke, air pollution, and workplace dust and chemical fumes. Smoke from fuels used for cooking and heating is a major risk factor in some places, particularly for women and young children. Diagnosis of COPD is usually confirmed using lung function tests that measure how well air moves in and out of the lungs.

As of 2021, COPD affected about 213 million people worldwide. COPD typically occurs in people over the age of 35–40, and risk increases with age. In 2021, COPD was the fourth-biggest cause of death, responsible for approximately 5% of total deaths. Almost 90% of COPD deaths in those under 70 years of age occur in low and middle income countries.

Signs and symptoms

The Global Initiative for Chronic Obstructive Lung Disease describes COPD as a lung condition that causes long-lasting symptoms like shortness of breath, cough, and mucus. These symptoms happen because the airways and small air sacs in the lungs become damaged, making it hard to breathe.

One main sign of COPD is feeling out of breath, especially during activities. This breathlessness can change during the day and might come with wheezing or a tight feeling in the chest. People often lean forward to help ease their breathing. Another common symptom is a chronic cough, which might bring up thick mucus. This cough can be worse in the morning and may continue for many years. Sometimes, the cough and mucus are triggered by infections, pollution, or smoking.

Other conditions

COPD often happens with other health problems, called comorbidities, affecting many parts of the body. People with COPD are more likely to have heart disease, lung infections like pneumonia, osteoporosis (weak bones), and conditions like depression, anxiety, and diabetes. These additional health issues can make managing COPD more challenging.

COPD also increases the risk of serious complications such as pneumonia, heart problems, and reduced quality of life. During the COVID-19 pandemic, people with COPD were more likely to have severe illness and long-term effects from the virus. Overall, having multiple health conditions alongside COPD can lead to more serious outcomes and earlier death compared to those without COPD.

Categorization

Categorizing COPD helps doctors choose the best treatments. COPD can look different in different people, and these differences are called phenotypes. One type, called emphysema, damages the air sacs in the lungs. Another type, chronic bronchitis, causes a lasting cough. Some people have a mix of both.

Doctors also study the causes behind these differences, called etiotypes. These include smoking, pollution, and genetic factors. Knowing the cause can help doctors manage the disease better and prevent future problems.

Causes

COPD develops because of long-term exposure to harmful particles or gases, like tobacco smoke, that irritate the lungs. This leads to inflammation and damage to the airways and lung tissue, making it harder to breathe over time. The biggest cause of COPD is smoking, whether a person smokes themselves or is exposed to secondhand smoke.

Other causes include air pollution, both outdoors and indoors, as well as exposure to dust and chemicals at work. Some people may also have a genetic tendency to develop COPD, making them more sensitive to these irritants. Poor lung development in early life can also increase the risk of COPD later on.

Pathophysiology

COPD is a long-term lung disease where the airways become narrower and the lung tissue gets damaged. This makes it hard to breathe because air can't move in and out easily. The tiny air sacs in the lungs, called small air sacs, lose their shape and can't transfer oxygen well into the blood. People with COPD often struggle to breathe out fully, which can make the lungs swell up more than normal.

The disease happens because the lungs react badly to things we breathe in, like smoke, leading to swelling and changes in the airway walls. This swelling and damage make it even harder to move air. The body also produces extra mucus that clogs the airways. Over time, this can cause the lungs to work less efficiently and may lead to other health problems.

Diagnosis

The diagnosis of COPD should be considered in anyone over the age of 35 to 40 who has shortness of breath, a chronic cough, coughing up mucus, or frequent winter colds, especially if they have been exposed to risk factors for the disease. Spirometry is used to confirm the diagnosis. This test measures how much air a person can move in and out of their lungs. It looks at two main numbers: how much air can be breathed out in the first second (FEV1) and the total amount of air that can be breathed out (FVC). If the ratio of these numbers is less than 70%, it helps to confirm COPD.

GOLD, an organization that studies COPD, updated its guidelines in 2023. They now focus on how severe the airflow limitation is, other symptoms, and past health issues when assessing COPD. They also look at how often a person’s symptoms get worse suddenly, which can be important for treatment decisions. Other tests like chest X-rays and CT scans can help rule out other conditions and show signs of COPD, but spirometry remains the main way to diagnose it.

Prevention

Many cases of COPD can be prevented by reducing exposure to tobacco smoke and other pollutants, both indoors and outdoors. Improving lung health early in life by avoiding frequent respiratory illnesses, poor nutrition, and low physical activity can also help prevent COPD later on.

Quitting smoking is one of the most important ways to prevent or slow the progression of COPD. Stopping smoking can improve lung function and quality of life, even if done later in the disease. Support from friends, smoking cessation programs, and medications can increase the chances of successfully quitting. Reducing exposure to harmful substances at work and improving air quality both at home and in public spaces are also key strategies to help prevent COPD.

Management

COPD currently has no cure, but treatments can help manage symptoms and slow its progression. Stopping smoking is very important and can make a big difference. If COPD is found early, when symptoms are mild, it can help prevent the disease from getting worse. Early diagnosis and treatment are key to improving quality of life and reducing flare-ups.

Management also includes reducing exposure to risk factors, such as offering help to stop smoking. Vaccinations, like the pneumococcal and influenza vaccines, are recommended to lower the risk of flare-ups. For those with severe COPD, palliative care focuses on relieving symptoms. Various medications are used, including bronchodilators, corticosteroids, and antibiotics, to help manage symptoms and exacerbations.

Procedures for emphysema

Main article: Lung volume reduction

There are several ways doctors can help people with severe emphysema, a type of lung disease, by reducing the size of the lungs. One way is through surgery called lung volume reduction surgery (LVRS). This surgery removes damaged lung tissue so the remaining lungs can work better. It is used when the disease is in the upper parts of the lungs and the person is otherwise healthy.

Another method uses special tools placed through the windpipe, known as bronchoscopic procedures. These include tiny one-way valves or coils that help shrink parts of the lung. There is also a technique using heated water vapor to reduce lung size. In very severe cases, a lung transplant might be an option. Doctors use special scans to decide the best treatment for each person.

Prognosis

COPD is a condition that gets worse over time and can affect a person’s health seriously. It is estimated that a small part of disability around the world is related to COPD, though improvements in air quality have helped reduce this in some areas.

Doctors use different tests to understand how COPD might affect someone in the future. They look at factors like weight, breathing difficulty, and how well a person can exercise, along with other health problems that might make the disease worse.

Epidemiology

Chronic obstructive pulmonary disease (COPD) affects millions of people around the world. In 2021, about 213 million people had COPD, which means about 2.7% of the world's population had the condition. The disease is more common in older adults, especially those over 60 years old. It can affect both men and women, but women who never smoked can also develop COPD more often than men.

The number of people with COPD changes in different countries depending on factors like smoking rates, air pollution, and the use of certain fuels for cooking. While the number of COPD cases and deaths has gone down a little worldwide since 1990, it is still a major cause of illness and death, especially in wealthier countries. In some places, more women are affected than men, which may be linked to changes in smoking habits over time.

History

Further information: Emphysema § History, and Chronic bronchitis § History

The name chronic obstructive pulmonary disease was first used in 1965. Before that, it had many other names. Two main parts of this disease, emphysema and chronic bronchitis, were defined in 1959 and 1962.

People have noticed problems with lungs for a long time. In the 1700s, doctors described lungs that were swollen with air. In the 1800s, a doctor invented a machine to measure how much air the lungs can hold.

In the 1900s, scientists learned that smoking could cause lung disease. They also began developing medicines to help people with this condition.

Society and culture

COPD is often not diagnosed, meaning many people don’t get treatment they might need. In the United States, November is recognized as COPD Awareness Month to help educate people about this condition.

The cost of treating COPD is very high. In 2010, it cost about $2.1 trillion worldwide, with much of this amount coming from medical care. Costs are expected to rise even more in the future. In Europe, COPD accounts for 3% of all healthcare spending. In the United States, the cost was around $50 billion in 2010, and in the United Kingdom, it was about £3.8 billion each year as of 2021.

Research

Researchers are exploring new ways to help people with chronic obstructive pulmonary disease (COPD). In June 2021, eight clinical trials had finished, and seventeen more were happening, looking at using stem cells to treat COPD. Scientists are also studying how to diagnose different types of COPD using special methods, and they are testing if remote healthcare can help people feel better and avoid trips to the emergency room.

People with COPD and their families think the most important research areas include helping families and communities, improving well-being, finding cures, developing new medical treatments, creating better policies, and using whole-body therapy approaches.

Other animals

Chronic obstructive pulmonary disease can also affect animals, often due to exposure to things like tobacco smoke. In horses, it is called recurrent airway obstruction or heaves, which is usually triggered by common allergens. This condition is also quite common in older dogs.