Also known as chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a group of diseases that affect your lungs and airways, causing breathing difficulties.

Key points

  1. COPD includes conditions such as emphysema, chronic bronchitis, certain types of bronchiectasis and, sometimes, asthma.
  2. The main cause of COPD is ongoing contact with substances that irritate and damage your lungs, most often through smoking.
  3. Symptoms tend to start slowly over a few years, so many people may have COPD but not realise it. Common symptoms include shortness of breath, ongoing cough and coughing up phlegm or mucus.
  4. People with COPD are at risk of getting chest infections and COPD is a common cause of hospital admissions.
  5. There is no cure for COPD, but there are things you can do to improve your symptoms and breathe more easily, such as quitting smoking, using your inhaler medicines and being up to date with your vaccinations.

How does COPD affect your lungs?

The 2 main conditions that cause COPD are emphysema and chronic bronchitis. They affect your lungs in different ways.

Your lungs, airways (bronchial tubes) and air sacs (alveoli) are elastic and 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.

  • Emphysema affects the air sacs. Over time, the air sacs are slowly destroyed, which makes it hard to absorb enough oxygen when you breathe.
  • Chronic bronchitis affects the large and small airways. They become inflamed, narrower and produce more mucus. This makes it harder to breathe.

Image credit: 123rf 

What causes COPD?

COPD is caused by long-term exposure to substances that can irritate and damage your lungs, such as smoking or certain types of fumes, dust and chemicals at work.


In New Zealand, nearly all COPD is caused by breathing in tobacco smoke, either directly by smoking or indirectly from second-hand smoke. Second-hand smoke is smoke that has been breathed out by a person smoking or that comes from the end of a lit tobacco product. About 1 in every 4 or 5 smokers will develop COPD. This is because harmful chemicals in smoke can damage the lining of your lungs and airways. If you are an ex-smoker, you remain at risk and should watch out for symptoms of breathlessness. Smoking and second-hand smoke exposure during your childhood and teenage years can slow lung growth and development. This can increase the risk of developing COPD in adulthood.

Fumes and dust at work

Exposure to certain types of dust and chemicals at work may damage your lungs and increase your risk of COPD. Substances that have been linked to COPD include welding fumes, cadmium dust and fumes, grain and flour dust, and silica dust. The risk of COPD is even higher if you breathe in dust or fumes in the workplace and you smoke.


About 1 in 100 people with COPD has a genetic tendency to develop COPD. This is called alpha-1-antitrypsin deficiency. Alpha-1-antitrypsin is a substance that protects your lungs. Without it, your lungs are more vulnerable to damage. People who have an alpha-1-antitrypsin deficiency usually develop COPD at a younger age, often under 35 – particularly if you smoke. Read more about alpha-1-antitrypsin deficiency.

What are the symptoms of COPD?

It is difficult to notice the symptoms of COPD at an early stage as they can be mild and may not occur all the time. The first symptoms of COPD tend to come on slowly, and people often mistake them as signs of ageing, lack of fitness or asthma. You may cough up mucus in the mornings or feel more short of breath than usual. Over time, the cough gets worse and occurs throughout the day.

As COPD progresses, you may gradually find it harder to do your normal daily activities, such as gardening, hanging out the washing or carrying groceries, without feeling short of breath.

Common symptoms of COPD include the following:
  • Ongoing cough, with or without mucus or phlegm.
  • Problems breathing, shortness of breath or breathlessness, at first only when you exert yourself, but over time even when resting.
  • Wheezing or chest tightness.
  • Increased phlegm or mucus, often thick and white or brownish in colour.
  • More chest infections.
  • Weight loss.
  • Fatigue and tiredness.

Your symptoms will be worse and become particularly severe during a flare-up. Read about COPD flare-up and how to manage it

How is COPD diagnosed?

Your doctor will take a history and may do lung function tests (spirometry) and blood tests. Imaging tests such as x-rays may be used to rule out other possible causes of breathing problems. Spirometry is the most commonly used test.

  • Spirometry measures the amount of air you are able to breathe in and out of your lungs, as well as how quickly you are able to breathe air out.
  • If you have COPD, you will usually take longer to breathe all the air out of your lungs as the airways become narrower.
  • Spirometry is also used to monitor how the condition is progressing, which is useful to help decide what treatment is suitable for you.

Read more about spirometry (Asthma Foundation, NZ)

How is COPD treated?

There is no cure for COPD. However, early diagnosis and treatment can help control your symptoms and prevent further permanent lung damage. There are also things you can do to help stop your condition getting worse.

Quit smoking

The best way to prevent COPD getting worse is to quit smoking. Although any damage done to your lungs and airways can't be reversed, giving up smoking can help prevent further damage. This may be all the treatment that's needed in the early stages of COPD, but even people with more advanced COPD can benefit from quitting. Read some tips to quit smoking.


Medications can help ease your symptoms so you breathe more easily. Inhalers deliver the medication directly into your lungs. This means smaller doses are needed and it can start working more quickly. Read more about medicines for COPD.

Pulmonary rehabilitation

Pulmonary rehabilitation is a specialised programme of exercise and education to help people with lung problems such as COPD. It can help improve how much exercise you're able to do before you feel out of breath, as well as improve your symptoms, self-confidence and emotional wellbeing. Read more about pulmonary rehabilitation.

How can I care for myself with COPD?

Self-care can improve your symptoms and quality of life. For smokers, quitting smoking is the only thing that has been proven to stop COPD from getting worse. Other things you can do to improve your symptoms include to:

  • have a COPD action plan
  • keep active
  • eat well
  • keep your home warm and dry
  • get vaccinated with the flu vaccine and pneumococcal vaccine.

Read more about self-care for COPD.

What support is available for people with COPD?

It can be distressing and frustrating to have breathing difficulties. Get help or find support when things are tough. Ask your GP about local support groups for COPD in your area. For more support services, see support services for COPD.

Learn more

The following links have more information about COPD. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

What is COPD?  Asthma & Respiratory Foundation, NZ
COPD and smoking Centre for Disease Control and Prevention, US
COPD – the essentials NHS Choices, UK
COPD NIH National Heart, Lung and Blood Institute, US
COPD – multicultural fact sheets Health Translations Directory, AU
COPD World Health Organization


  1. The COPD prescribing tool BPAC, NZ, 2017
  2. Tips for prescribing newly-subsidised medicines for patients with COPD BPAC, NZ, 2016
  3. Global initiative for chronic obstructive lung disease 2018 

Reviewed by

Dr Sharon Leitch is a general practitioner and clinical research training fellow in the Department of General Practice and Rural Health at the University of Otago. Her area of research is patient safety in primary care and safe medicine use.
Credits: Health Navigator Editorial Team . Reviewed By: Dr Sharon Leitch, GP and University of Otago clinical research training fellow Last reviewed: 17 Apr 2020