What is the major cause of chronic obstructive pulmonary disease?

COPD, or chronic obstructive pulmonary disease, is a progressive disease, which means it gets worse over time. With COPD, less air flows in and out of the airways, making it hard to breathe.

COPD Basics (3:52)
Learn who is at risk for COPD, what symptoms to watch for, and how the disease affects the lungs. 

In the United States, COPD affects more than 15 million adults, and many more do not know they have it. More than half of those diagnosed are women. COPD is a major cause of disability, and it is the fourth leading cause of death in the United States according to the Centers for Disease Control and Prevention (CDC).

The good news is that COPD can often be prevented, mainly by not smoking. Cigarette smoking is the leading cause of COPD. Most people who have COPD smoke or used to smoke. However, up to 30% of people with COPD never smoked. A rare genetic condition called alpha-1 antitrypsin (AAT) deficiency can also cause the disease.

In the United States, the term COPD includes two main conditions.

  • Emphysema develops when there’s damage to the walls between many of the air sacs in the lungs. Normally, these sacs are elastic or stretchy. When you breathe in, each air sac fills up with air, like a small balloon. When you breathe out, the air sacs deflate, and the air goes out. In emphysema, it is harder for your lungs to move air out of your body.
  • Chronic (long-term) bronchitis is caused by repeated or constant irritation and inflammation in the lining of the airways. Lots of thick mucus forms in the airways, making it hard to breathe.

Most people who have COPD have both emphysema and chronic bronchitis, but how serious each condition is varies from person to person.

COPD can cause coughing that produces large amounts of a slimy substance called mucus. It can also cause problems breathing, shortness of breath, chest tightness, and other symptoms. Symptoms of COPD often develop slowly but worsen over time, and they can limit your ability to do routine activities. Serious COPD may prevent you from doing even basic activities like walking, cooking, or taking care of yourself.

Although there is no cure, treatments and lifestyle changes such as quitting smoking can help you feel better, stay more active, and slow the progress of the disease. You may also need oxygen therapy, pulmonary rehabilitation, or medicines to treat complications.

What is the major cause of chronic obstructive pulmonary disease?

Brochure

A Quick Guide on COPD

This guide provides an overview of COPD and its symptoms.

Chronic Obstructive Pulmonary Disease (COPD) is a serious medical condition and is the 10th leading cause of death in Singapore.1The most important cause of COPD is cigarette smoking. Thus, not smoking cigarettes is the best way to prevent COPD and quitting smoking is the best way to stop the progression of this disease. 


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Chronic obstructive pulmonary disease (COPD) is a common lung disease. Having COPD makes it hard to breathe.

There are two main forms of COPD:

  • Chronic bronchitis, which involves a long-term cough with mucus
  • Emphysema, which involves damage to the lungs over time

Most people with COPD have a combination of both conditions.

Smoking is the main cause of COPD. The more a person smokes, the more likely that person will develop COPD. But some people smoke for years and never get COPD.

If a person has a rare condition in which they lack a protein called alpha-1 antitrypsin, they can develop emphysema even without smoking.

What is the major cause of chronic obstructive pulmonary disease?

Other risk factors for COPD are:

  • Exposure to certain gases or fumes in the workplace
  • Exposure to heavy amounts of secondhand smoke and pollution
  • Frequent use of a cooking fire without proper ventilation

Symptoms may include any of the following:

  • Cough, with or without mucus
  • Fatigue
  • Frequent respiratory infections
  • Shortness of breath (dyspnea) that gets worse with mild activity
  • Trouble catching one's breath
  • Wheezing

Because the symptoms develop slowly, many people may not know that they have COPD.

The best test for COPD is a lung function test called spirometry. This involves blowing out as hard as possible into a small machine that tests lung capacity. The results can be checked right away.

What is the major cause of chronic obstructive pulmonary disease?

Using a stethoscope to listen to the lungs can also be helpful, showing prolonged expiratory time or wheezing. But sometimes, the lungs sound normal, even when a person has COPD.

Imaging tests of the lungs, such as x-rays and CT scans may be ordered. With an x-ray, the lungs may look normal, even when a person has COPD. A CT scan will almost always show signs of COPD if it is present.

Sometimes, a blood test called arterial blood gas may be done to measure the amounts of oxygen and carbon dioxide in the blood.

If your health care provider suspects you have alpha-1 antitrypsin deficiency, a blood test will likely be ordered to detect this condition.

There is no cure for COPD. But there are many things you can do to relieve symptoms and keep the disease from getting worse.

If you smoke, now is the time to quit. This is the best way to slow lung damage.

Medicines used to treat COPD include:

  • Quick-relief drugs to help open the airways
  • Control drugs to reduce lung inflammation
  • Anti-inflammatory drugs to reduce swelling in the airways
  • Certain long-term antibiotics

In severe cases or during flare-ups, you may need to receive:

  • Steroids by mouth or through a vein (intravenously)
  • Bronchodilators through a nebulizer
  • Oxygen therapy
  • Assistance from a machine to help breathing by using a mask or through the use of an endotracheal tube

Your provider may prescribe antibiotics during symptom flare-ups, because an infection can make COPD worse.

You may need oxygen therapy at home if you have a low level of oxygen in your blood.

Pulmonary rehabilitation does not cure COPD. But it can teach you more about the disease, train you to breathe in a different way so you can stay active and feel better, and keep you functioning at the highest level possible.

LIVING WITH COPD

You can do things every day to keep COPD from getting worse, protect your lungs, and stay healthy.

Walk to build up strength:

  • Ask the provider or therapist how far to walk.
  • Slowly increase how far you walk.
  • Avoid talking if you get short of breath when you walk.
  • Use pursed lip breathing when you breathe out, to empty your lungs before the next breath.

Things you can do to make it easier for yourself around the home include:

  • Avoid very cold air or very hot weather
  • Make sure no one smokes in your home
  • Reduce air pollution by not using the fireplace and getting rid of other irritants
  • Manage stress and your mood
  • Use oxygen if prescribed for you

Eat healthy foods, including fish, poultry, and lean meat, as well as fruits and vegetables. If it is hard to keep your weight up, talk to a provider or dietitian about eating foods with more calories.

Surgery or other interventions may be used to treat COPD. Only a few people benefit from these surgical treatments:

  • One-way valves can be inserted with a bronchoscopy to help deflate parts of the lung that are hyperinflated (overinflated) in select patients.
  • Surgery to remove parts of the diseased lung, which can help less-diseased parts work better in some people with emphysema (lung volume reduction surgery).
  • Lung transplant for a small number of very severe cases.

You can ease the stress of illness by joining a support group. Sharing with others who have common experiences and problems can help you not feel alone.

COPD is a long-term (chronic) illness. The disease will get worse more quickly if you do not stop smoking.

If you have severe COPD, you will be short of breath with most activities. You may be admitted to the hospital more often.

Talk with your provider about breathing machines and end-of-life care as the disease progresses.

With COPD, you may have other health problems such as:

  • Irregular heartbeat (arrhythmia)
  • Need for breathing machine support with a mask (non-invasive ventilation) and oxygen therapy
  • Right-sided heart failure or cor pulmonale (heart swelling and heart failure due to chronic lung disease)
  • Pneumonia
  • Collapsed lung (pneumothorax)
  • Severe weight loss and malnutrition
  • Thinning of the bones (osteoporosis)
  • Debilitation
  • Increased anxiety

Go to the emergency room or call 911 or the local emergency number if you have a rapid increase in shortness of breath.

Not smoking prevents most COPD. Ask your provider about quit-smoking programs. Medicines are also available to help you stop smoking.

COPD; Chronic obstructive airways disease; Chronic obstructive lung disease; Chronic bronchitis; Emphysema; Bronchitis - chronic

Global Initiative for Chronic Obstructive Lung Disease (GOLD) website. Global strategy for prevention, diagnosis and management of COPD: 2022 Report. goldcopd.org/2022-gold-reports-2/. Accessed July 13, 2022.

Han MK, Lazarus SC. COPD: diagnosis and management. In: Broaddus VC, Ernst JD, King TE, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 64.

National Institutes of Health, National Heart, Lung, and Blood Institute website. COPD national action plan. www.nhlbi.nih.gov/sites/default/files/media/docs/COPD%20National%20Action%20Plan%20508_0.pdf. Updated February 2021. Accessed July 13, 2022.

Rochester CL, Nici L. Pulmonary rehabilitation. In: Broaddus VC, Ernst JD, King TE, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 7th ed. Philadelphia, PA: Elsevier; 2022:chap 139.

Updated by: Denis Hadjiliadis, MD, MHS, Paul F. Harron Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

What is the major cause of chronic obstructive pulmonary disease COPD and chronic bronchitis?

Over time, exposure to irritants that damage your lungs and airways can cause chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema. The main cause of COPD is smoking, but nonsmokers can get COPD too.

What are the 3 main symptoms of chronic obstructive pulmonary disease?

Main symptoms.
increasing breathlessness – this may only happen when exercising at first, and you may sometimes wake up at night feeling breathless..
a persistent chesty cough with phlegm that does not go away..
frequent chest infections..
persistent wheezing..