COPD: symptoms, causes, diagnosis and living well, a review

Chronic obstructive pulmonary disease, usually called COPD, is a long-term lung condition that can go unnoticed. This article explains what COPD is, what causes it, how it is diagnosed and how it is managed, using information from the NHS, MedlinePlus and the World Health Organization (WHO).

1. Introduction

COPD is a group of long-term lung diseases that make breathing difficult and tend to get worse over time ^[2]. The NHS says it mostly affects middle-aged and older adults who smoke, and many people do not realise they have it ^[1]. WHO describes it as the third leading cause of death worldwide, with about 3.4 million deaths in 2023 ^[3].

Two conditions are usually included under the name COPD ^{[1, 2]}:

• Emphysema, in which the tiny air sacs in the lungs and their walls are damaged.
• Chronic bronchitis, in which the lining of the airways stays irritated and swollen and makes extra mucus.

Most people have features of both, to different degrees ^[2].

2. Signs and symptoms

In the early stages there may be few or no symptoms. Over time they usually grow stronger. The main signs are ^{[1, 2]}:

• Shortness of breath, especially when active
• A cough that does not go away, sometimes with mucus (phlegm), which some people dismiss as a "smoker's cough"
• Wheezing or a whistling sound when breathing
• Chest tightness and tiredness
• Frequent chest infections, colds and flu

A flare-up (also called an exacerbation) is a sudden worsening of symptoms. WHO says flare-ups usually last a few days and often need additional medicine ^[3]. In advanced disease, weight loss, weakness in the lower muscles and swelling in the ankles, feet and legs can occur ^[2].

3. Causes and risk factors

COPD usually develops slowly after long exposure to things that irritate the lungs.

• Smoking is the main cause. The NHS says risk rises with the amount smoked and the number of years ^[1]. Pipe, cigar and other tobacco smoke, and secondhand smoke, can also contribute ^{[2, 3]}.
• Air pollution and fumes. Long-term exposure to dust, fumes or chemicals at work can cause COPD ^{[1, 2]}. WHO points out that indoor smoke from cooking or heating with wood, dung, crop waste or coal is a major cause in many low- and middle-income countries, where tobacco accounts for only 30 to 40 percent of cases ^[3].
• Early life. Being born early or with low birth weight, and serious childhood chest infections, can limit lung growth ^[3].
• A rare inherited condition, alpha-1 antitrypsin deficiency, can make the lungs more open to damage, sometimes at a young age ^{[1, 2, 3]}.

COPD can sometimes affect people who have never smoked ^[1]. People with a history of asthma are at higher risk, although most people with asthma never develop COPD ^[2]. COPD and asthma can overlap, and some people have both ^[3].

4. Diagnosis and tests

The NHS advises seeing a doctor about persistent symptoms, especially if you are over 35 and smoke or used to smoke ^[1]. The doctor will ask about your symptoms and your smoking and exposure history. WHO explains that the diagnosis is confirmed with spirometry, a breathing test that shows how well the lungs are working ^[3]. It also notes that spirometry is often not available in low- and middle-income countries, so the diagnosis may be missed ^[3].

MedlinePlus says other tests may include lung function tests, a chest X-ray or CT scan, and blood tests. The blood tests may include an arterial blood gas test or a test for alpha-1 antitrypsin deficiency ^[2].

5. Treatment and management

The lung damage in COPD is permanent, but the NHS says treatment can slow how fast it gets worse ^[1]. MedlinePlus says treatment can ease symptoms, help you stay active and prevent or manage complications ^[2]. Your doctor decides which of these are right for you.

• Stopping smoking is described as the most important step by the NHS, MedlinePlus and WHO. Quitting helps even after many years of smoking ^{[1, 2, 3]}.
• Inhaled medicines. Bronchodilators relax the muscles around the airways and make breathing easier. Some people also use inhaled steroids to reduce swelling ^{[2, 3]}.
• Treatment of flare-ups. Steroid tablets and antibiotics may be used when a flare-up is caused by infection ^{[2, 3]}.
• Pulmonary rehabilitation. This is a structured programme of exercise, breathing training, education, nutrition advice and emotional support ^{[1, 2, 3]}.
• Oxygen therapy for people with severe disease and low blood oxygen ^{[2, 3]}.
• Surgery or lung transplant. These are used for only a small number of people with severe disease ^{[1, 2]}.

Correct inhaler technique matters, and a spacer device may help ^[3].

6. Prevention and self-care

COPD is largely preventable. The best protection is to avoid smoking or vaping, and to avoid secondhand smoke, smoke from indoor cooking fires and workplace dust and fumes ^{[1, 2, 3]}. Other useful steps are:

• Stay as active as your condition allows ^{[2, 3]}.
• Eat a diet that meets your needs ^[2].
• Get yearly flu shots, pneumonia vaccines and up-to-date COVID-19 vaccines, as advised by your doctor ^{[2, 3]}.
• Learn about your condition, your treatment and self-care so you can stay as active and healthy as possible ^[3].

7. Special groups

People with COPD have a higher risk of lung infections, lung cancer, heart problems, weak muscles and brittle bones, and depression and anxiety ^[3]. Tell your doctor if you feel low or worried, because help is available. Younger people with an inherited cause, and people who never smoked but breathed smoke or fumes for years, can also be affected ^{[1, 2, 3]}.

8. When to see a doctor

See a doctor if you have a cough that does not go away, breathlessness, wheezing or repeated chest infections, especially if you smoke or used to ^[1]. Early advice helps protect the lungs from further damage ^[1]. If you already have COPD, contact your doctor when symptoms are getting worse or if you have signs of infection such as fever ^[2]. Seek urgent help for severe symptoms, such as trouble catching your breath or speaking ^[2].

In an emergency, call your local emergency number (112 in India, 911 in the United States).

9. Conclusion

COPD is a common, long-term lung condition, most often caused by smoking and by polluted air. The damage cannot be reversed, but stopping smoking, taking medicines as advised, staying active, getting vaccines and joining pulmonary rehabilitation can help people feel better and slow its progress.