What causes COPD? Diagnosis, prevention, and treatment

Chronic obstructive pulmonary disease (COPD) is a lung disease that causes a blockage in airflow and breathing problems. It includes chronic bronchitis and emphysema. Common symptoms are difficulty breathing, chronic cough, most often with phlegm, and wheezing. 

COPD is quite common. In the United States, over 16 million people have COPD. There are millions more who have the disease but haven’t been diagnosed. In fact, in 2018, COPD was the fourth leading cause of death in the U.S. People aged 40 years and older, current or former smokers, and people with a history of asthma are more likely to suffer from COPD. 

There is no cure for COPD, but there are treatments that can manage symptoms and keep the disease from worsening.

What causes COPD?

The main cause of COPD is tobacco smoking. However, it’s possible for people who never smoked also to develop COPD. Other causes of COPD include sources of lung irritants, such as air pollution, exposure from the workplace, and a rare genetic condition called alpha-1 antitrypsin (AAT) deficiency.

Smoking

It’s estimated that about 75% of people with COPD have a smoking history. Tobacco smoke has harmful chemicals that can weaken, inflame, and narrow the airways – all contributing factors to COPD. When smoke reaches the lungs, it irritates the airways, which triggers inflammation. This brings out a response from the body’s immune system. White blood cells are sent to the lungs, releasing strong enzymes. Healthy lungs can usually protect themselves from these enzymes, but smoke weakens the body’s defenses, and these enzymes ultimately destroy lung tissue, causing COPD. The more or longer someone smokes, the higher the chance they will develop lung damage causing COPD. 

Air pollution

Long-term exposure to dust, fumes, or chemicals can raise the risk of COPD. Sources of air pollution include motor vehicles, wood-burning fireplaces, and wildfires.

Workplace exposure

COPD causes also include long-term exposure to chemicals and fumes in the workplace. Examples of harmful materials at work are ammonia, asbestos, and carbon monoxide. 

AAT deficiency

Alpha-1 antitrypsin (AAT) deficiency is a rare genetic disorder that can cause COPD at a young age. AAT is a protein made in the liver that protects the lungs from inflammation and damage. If your body doesn’t make enough AAT, your lungs are at higher risk of being damaged by irritants such as smoking or pollution. This can lead to COPD. 

Risk factors for COPD

The leading cause of COPD is smoking. But people who never smoke can also develop COPD. Other factors can raise the risk of developing COPD. These include: 

• Exposure to secondhand smoke

• Exposure to coal or wood-burning stoves

• Exposure to air pollution

• Exposure to dust, fumes, and chemicals in the workplace

• History of lung infections as a child

• History of asthma

• Underdeveloped lungs

• Age 40 and older

• Lack of access to healthcare

• Poverty

• Residing in a rural area

• Genetics, such as AAT deficiency

Is COPD serious? When to see a doctor

Signs and symptoms of COPD include a persistent cough with mucus, trouble taking a deep breath, and shortness of breath (during regular activity or during mild physical activity). It’s a progressive disease, meaning it’s a medical condition that gets worse over time. In the early stages, COPD symptoms may be mild. You can have symptoms such as occasional shortness of breath, mild cough, or having to clear your throat. The early stage can typically be managed with medications and specific lifestyle choices. But as the disease worsens, symptoms may limit your quality of life. The symptoms can get more severe and constant, so breathing can feel difficult. Some people with COPD may also experience acute flare-ups and sudden episodes of severe symptoms. This is called a COPD exacerbation. 

People with COPD are also at higher risk of certain complications. These include: 

Respiratory infections

People with COPD have a higher chance of getting sick with colds, the flu, and pneumonia. These illnesses can make breathing even more difficult and further irritate the lungs.

Depression

COPD can make it difficult to participate in activities you enjoy. This can be isolating and contribute to the development of depression.

Heart disease and heart attack

COPD also raises the risk of heart disease and heart attacks. Heart disease causes symptoms similar to COPD, including shortness of breath and fatigue. 

Lung cancer

People with COPD have a higher chance of developing lung cancer. 

High blood pressure in the lung vessels

COPD can raise the pressure in the blood vessels between the heart and the lungs. This is called pulmonary hypertension. 

Due to these risks, any symptoms or signs of COPD should be reported to your healthcare provider, even if they aren’t severe or you aren’t feeling sick. Examples of symptoms that should be reported to your healthcare provider within 24 hours include:

• Worsening or more frequent shortness of breath

• Changes in color, thickness, odor, or amount of sputum

• Blood in the phlegm

• More frequent coughing or wheezing

• New or worsening swollen ankles, feet, or legs

• Unexplained weight loss or gain (2 lbs in a day or 5 lbs in a week)

• Fever

• Extreme fatigue or weakness that lasts longer than a day

Severe symptoms of COPD or a COPD exacerbation require emergency medical help. If you have any of the following symptoms, call 911:

• Confusion, disorientation, or difficulty speaking

• Severe shortness of breath or chest pain

• Bluish-colored lips or fingers

How is COPD diagnosed?

A healthcare provider can diagnose someone with COPD based on their medical history, symptoms, physical exam, and breathing or lung tests. 

Medical history

Doctors will ask questions about your medical history to diagnose COPD. Examples of questions include: 

• Do you smoke?

• Have you had long-term exposure to secondhand smoke?

• What line of work are you in? 

• Have you been exposed to harmful dust, fumes, or chemicals for long periods of time?

• Is there a history of COPD in your family?

• Do you have a history of asthma or other respiratory conditions?

Symptoms

Be sure to mention all of your symptoms to your healthcare provider. They may also ask you questions such as:

• How long have you been coughing or wheezing?

• Do you cough up phlegm?

• What type of activities cause difficulty breathing?

Physical exam

Your provider will perform a physical exam to listen to your lungs while breathing. They’ll likely check your blood pressure and pulse and look for any swelling in your feet and ankles. 

Tests

Your doctor will perform spirometry to test your lung function. To perform the test, you will take as big and deep a breath as possible and blow out as hard and fast as possible into a tube connected to a spirometer. In addition to spirometry, your healthcare provider may run tests such as a test to determine your oxygen levels, chest X-ray or chest CT scan, electrocardiogram (ECG), blood tests, and exercise testing.

Is COPD hereditary?

While smoking is the leading cause of COPD, it’s not the only cause. COPD typically isn’t hereditary, but in rare cases, it can be linked to a heritable genetic disorder called alpha-1 antitrypsin (AAT) deficiency. AAT deficiency is when you have low levels of a protein, AAT, that protects the lungs. Without adequate amounts of this protein, your chances of developing COPD are higher. 

Is COPD curable?

COPD isn’t curable, but medications and certain lifestyle choices can manage symptoms and slow the progression of the disease. 

There are many options for COPD treatment. Examples include medications, pulmonary rehabilitation, oxygen therapy, and surgery, such as a lung transplant. Inhalers are typically one of the first treatment options healthcare providers will prescribe. There are several types of medications that can manage COPD. These include:

• Bronchodilators

• Inhaled corticosteroids

• Phosphodiesterase-4 inhibitors

• Xanthines

• Mucolytics

• Anticholinergics

• Leukotriene modifiers

How to prevent COPD

Since smoking is the leading cause of COPD, the best way to prevent COPD is never to smoke or quit smoking. Your healthcare provider can recommend products, medications, or support programs that may help. Limiting exposure to air pollutants at home or work can also lower your risk of COPD. 

COPD exacerbations can be serious and require medical attention. So, it’s best to try and prevent them from happening. The best way to do this is to avoid anything that makes your COPD worse. This is called a COPD trigger. To do this, you’ll need to understand which triggers make your COPD worse and then create an action plan to avoid these triggers. Examples of common COPD triggers include cigarette smoke, dust, chemicals, fumes, weather, pollen, and lung infections such as a cold or the flu. You can work with your healthcare provider to make a plan to avoid COPD triggers. 

RELATED: What are my options for OTC and prescription smoking cessation drugs

What’s next? Additional resources for people with COPD

Test and diagnostics

• Chronic obstructive pulmonary disease (COPD), Cleveland Clinic

Treatments

• COPD treatments and medications, SingleCare

Scientific studies and clinical trials

• Clinical trials for COPD, American Lung Association

More information on related health conditions

• Asthma treatments and medications, SingleCare

Sources

• About heart disease, Centers for Disease Control and Prevention (2023)

• Alpha-1 antitrypsin deficiency, Cleveland Clinic (2022)

• Alpha-1 antitrypsin deficiency, National Heart, Lung, and Blood Institute (2022)

• Basics about COPD, Centers for Disease Control and Prevention (2023)

• Chronic obstructive pulmonary disease, Centers for Disease Control and Prevention (2023)

• Chronic obstructive pulmonary disease (COPD), Cleveland Clinic (2022)

• Chronic obstructive pulmonary disease (COPD), World Health Organization (2023)

• Chronic obstructive pulmonary disease (COPD) national trends, Centers for Disease Control and Prevention (2022)

• COPD, Mayo Clinic (2020)

• COPD causes and risk factors, American Lung Association (2023)

• Prevent COPD exacerbations or flare ups, American Lung Association (2023)

• Pulmonary hypertension, Centers for Disease Control and Prevention (2019)

• Pulmonary rehabilitation, American Lung Association (2023)

• Spirometry, American Lung Association (2023)

• Understanding COPD exacerbations, COPD Step by Step (n.d.)

• What causes COPD, COPD Foundation (2020)