What Is Chronic Obstructive Pulmonary Disease (COPD)?

Chronic obstructive pulmonary disease, or COPD, is a long-term inflammatory lung condition that causes shortness of breath and breathing problems. COPD is a collective group of conditions, including emphysema and chronic bronchitis, that develops over time from damage to the lungs from smoking and environmental pollution.

This article will overview the types of COPD; how COPD affects the body; its symptoms, diagnosis, treatment; and helpful resources for living with COPD.

Nurse checking patient's lungs

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How COPD Affects the Body

COPD occurs when damage to the lungs causes chronic lung inflammation. This inflammation results in an obstructive lung problem in which it is difficult to exhale enough air from the body. Inflammation that occurs with COPD produces lung changes that include:

  • Airflow limitation: Inflamed airways restrict the amount of air that can flow into and out of the lungs. This lowers your FEV1, a measure of how much air you can exhale.
  • Air trapping: Because air is obstructed from leaving the lungs, air can get trapped in the lungs. This leads to hyperinflation of the lungs, causing shortness of breath and a barrel chest.
  • Gas exchange problems: Damage to the air sacs called alveoli within the lungs throws off the balance of gas exchange between oxygen and carbon dioxide, causing decreased oxygen throughout the body.
  • Increased mucus production: Chronic lung irritation causes more mucus to form in the airways. This further narrows the airways and obstructs the flow of air, worsening shortness of breath.

Types of COPD

COPD is primarily classified into two types, as follows:

  • Emphysema: A condition caused by damage to the walls between the air sacs (alveoli) of the lungs, making it difficult to move air in and out of the body. Emphysema most often occurs from cigarette smoking.
  • Chronic bronchitis: A condition caused by repeated irritation to the lining of the airways, resulting in chronic inflammation and mucus production that makes it hard to breathe. 

COPD Symptoms

COPD causes symptoms that affect your lungs, airways, and your ability to breathe. Some symptoms present in the beginning while others worsen over time. 

Early Signs

Early signs of COPD include noticeable changes in how you breathe. You may notice feeling winded or getting short of breath, especially with physical activity. An ongoing cough or coughing up a lot of mucus are also common. 

Progressive COPD

As COPD progresses and gets worse, symptoms become more frequent and severe. Shortness of breath can occur at rest even without increased demands from physical activity. You may also experience chest tightness and fatigue from having to try harder to breathe. 

Symptoms of COPD Exacerbation

A COPD exacerbation is a period of worsened symptoms often triggered by a respiratory infection or environmental pollution. Exacerbations related to viral infections tend to result in more severe symptoms that last longer and require more treatment, including hospitalization.

Additional symptoms of COPD exacerbations include:

  • High respiratory rate more than 25 breaths per minute 
  • High heart rate more than 110 beats per minute
  • Low oxygen saturation in the blood less than 90%

What Causes COPD?

COPD is caused by long-term exposure to irritants that inflame and damage the lungs and airways. The most common cause of COPD is cigarette smoking, although exposure to environmental pollution can also cause COPD.

Factors that increase your risk of developing COPD include:

  • Exposure to air pollution or hazardous dust, fumes, and chemicals
  • Breathing in secondhand smoke
  • Alpha-1 deficiency, a genetic condition that affects the body’s ability to produce a protein that protects the lungs
  • A history of respiratory infections during childhood 

How Is COPD Diagnosed?

Patients with a history of smoking, environmental pollution or hazard exposure, and symptoms like shortness of breath and ongoing cough should all be screened for COPD. An official COPD diagnosis is made through a breathing test called spirometry. 

Spirometry is a pulmonary function test that examines how well your lungs are working. You will forcefully breathe out into the tube of a spirometer, a device that measures the force and amount of air that you can exhale. This will calculate your forced expiratory volume (FEV1). A diagnosis of COPD is made if your FEV1 is less than 80%.

Stages of COPD

According to the Global Initiative for Chronic Obstructive Lung Disease, the four stages of COPD classified by your FEV1 level are:

  • GOLD stage 1 (mild): FEV1 predicted of greater than or equal to 80% 
  • GOLD stage 2 (moderate): FEV1 of greater than or equal to 50% but less than 80%
  • GOLD stage 3 (severe): FEV1 of greater than or equal to 30% but less than 50%
  • GOLD stage 4 (very severe): FEV1 of less than 30%

COPD Treatment

COPD symptoms can have a significant impact on your quality of life, so treatment is important for maintaining independence with your daily activities. Avoiding triggers is the most important part of treatment, but if your condition is severe, more involved treatment methods like oxygen therapy and surgery may be needed.


Because 85–90% of cases of COPD develop in smokers, stopping smoking is extremely important for managing symptoms and preventing exacerbations and progression of COPD. Consider joining an in-person or online smoking cessation program to help.

Avoiding exposure to air pollution, whenever possible, can also help decrease airway inflammation and reduce your severity of symptoms.


Medication that opens up your airways and decreases coughing and wheezing can help improve your ability to breathe. These include drugs like long-acting beta 2 agonists (LABAs) and long-acting muscarinic antagonists (LAMAs).

Staying healthy through regular vaccinations can also help decrease your risk of respiratory infections and decrease the likelihood of developing a COPD exacerbation. Inhaled corticosteroids may also be used to treat inflammation in the airways, often in combination with LABAs and LAMAs.

Certain medications can also be used to help you stop smoking, including varenicline, sustained-release bupropion, nortriptyline, nicotine gum, nicotine inhaler, nicotine nasal spray, and nicotine patches.

Oxygen Therapy 

If your breathing is significantly impaired and your blood oxygen level is too low, you may need supplemental oxygen to help you breathe. This will involve wearing plastic tubing called a nasal cannula connected to an oxygen tank or portable oxygen unit that delivers a steady flow of oxygen into your airways.


Surgery for COPD may ultimately be needed if your condition is severe, and your lung function is significantly impaired. Surgical procedures for COPD may include:

  • Bullectomy: A procedure to remove bullae, large clusters of destroyed alveoli that block the flow of air in the lungs.
  • Lung volume reduction surgery (LVRS): A procedure to remove diseased lung tissue to improve the function of the remaining portion of the lungs.
  • Lung transplant: A procedure to implant a new lung from an organ donor to replace a severely damaged and malfunctioning lung.

Secondary COPD Complications

COPD often coexists with other medical conditions that can worsen symptoms of COPD. These include conditions like heart disease, bronchiectasis, chronic kidney disease, high cholesterol and/or triglycerides (dyslipidemia), diabetes, high blood pressure, lung cancer, obstructive sleep apnea, stroke, and heart attack.

While there aren't exact rules that can determine how long a person can live with COPD, the BODE index (standing for body mass, obstruction of airflow, dyspnea or difficulty breathing, and exercise capacity) can help predict your life expectancy. The lower your BODE Index, the better your prognosis.

COPD Support and Resources 

You shouldn't have to go through living with COPD alone. Support groups through online forums, chat rooms, and in-person and virtual meetings can help you manage your condition and promote a healthier lifestyle, including working to stop smoking or decrease your tobacco use.

Living a Healthy Life With COPD

Practicing healthy lifestyle measures can make it easier to live with COPD and reduce your symptoms and risk of exacerbations. Regular exercise, in particular, can help improve your breathing and lung function and overall health. Staying connected to others, reducing stress, and sticking to your medical treatments as prescribed by your healthcare provider can help keep you healthy and active.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Kristen Gasnick, PT, DPT
Kristen Gasnick, PT, DPT, is a medical writer and a physical therapist at Holy Name Medical Center in New Jersey.