Chronic Obstructive Pulmonary Disease (COPD)

## Overview Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung condition characterised by persistent respiratory symptoms and airflow obstruction arising from abnormalities of the airways and/or alveoli. It commonly develops following prolonged exposure to harmful particles or gases and may progressively limit a person's ability to breathe and carry out everyday activities. COPD includes different patterns of lung damage, particularly small-airway disease and emphysema. Chronic bronchitis describes a clinical pattern of chronic cough with sputum production, while emphysema describes destruction of the alveolar walls. These terms are related to COPD but are not interchangeable with the full disease diagnosis. ## Key clinical points 1. **Typical symptoms:** Breathlessness, persistent cough, sputum production, wheezing and fatigue are common. Symptoms may develop gradually and worsen over time. 2. **Important risk factors:** Tobacco smoke is a major risk factor, but COPD also occurs in people exposed to household air pollution, biomass-fuel smoke, occupational dusts, chemicals and fumes, and outdoor air pollution. 3. **Diagnosis requires spirometry:** COPD should be suspected in people with compatible respiratory symptoms and relevant exposure or risk factors. Post-bronchodilator spirometry demonstrating an FEV₁/FVC ratio below 0.70 supports confirmation of persistent airflow obstruction in the appropriate clinical context. 4. **Assess more than airflow obstruction:** Clinical assessment should consider symptom burden, previous exacerbations, functional limitation, nutritional status and coexisting conditions. 5. **Smoking cessation and exposure reduction matter:** Stopping tobacco use and reducing exposure to harmful airborne substances are important components of prevention and long-term management. 6. **Treatment is individualised:** Inhaled bronchodilators are central to symptom management. Treatment selection depends on symptoms, exacerbation history, clinical assessment and response to therapy. Inhaled corticosteroids are appropriate for selected patients rather than automatically required for everyone with COPD. 7. **Non-pharmacological care is important:** Pulmonary rehabilitation, physical activity, vaccination, nutritional support where needed, and education about inhaler technique can contribute to better outcomes. 8. **Exacerbations require attention:** A COPD exacerbation is an acute worsening of respiratory symptoms beyond normal day-to-day variation. Severe or rapidly worsening breathlessness, confusion, cyanosis or signs of respiratory distress require urgent medical assessment. ## Global health significance COPD is a major global cause of illness and premature death. The World Health Organization reported approximately 3.4 million COPD-related deaths worldwide in 2023, representing about 6% of all global deaths. The burden is particularly important in low- and middle-income countries, where household air pollution and other non-tobacco exposures contribute substantially. ## Clinical reminder COPD and asthma can share symptoms, and some people may have features of both conditions. A careful clinical history, appropriate investigations and objective lung-function assessment are important when distinguishing them. This information is for medical education and does not replace individual clinical assessment or treatment decisions.

## Overview COPD commonly causes persistent respiratory symptoms that develop gradually and may become more limiting over time. The pattern and severity of symptoms vary between individuals and may be influenced by the extent of airway and lung damage, other medical conditions and exposure to respiratory irritants. ## Common symptoms - **Breathlessness (dyspnoea):** Often initially noticed during physical activity, such as walking uphill or climbing stairs. As the disease progresses, breathlessness may occur during lighter activity or at rest. - **Chronic cough:** A persistent cough may be present, with or without sputum production. - **Sputum production:** Some people regularly cough up mucus. The amount and character may vary. - **Wheezing:** A whistling sound during breathing may occur because of narrowed airways. - **Chest tightness:** Some individuals describe a sensation of tightness or discomfort in the chest. - **Fatigue:** Increased effort required for breathing, reduced physical activity and associated health conditions may contribute to tiredness. - **Reduced exercise tolerance:** Activities that were previously manageable may become increasingly difficult. Not everyone with COPD experiences all these symptoms. Some people have significant airflow obstruction with relatively few reported symptoms, while others experience substantial functional limitation. ## Symptoms of an acute exacerbation A COPD exacerbation is an acute worsening of respiratory symptoms beyond normal day-to-day variation. Features may include: - Increased breathlessness. - Increased cough. - Increased sputum volume. - A change in sputum colour or purulence. - Increased wheezing or chest tightness. - Reduced ability to perform usual daily activities. Exacerbations may be associated with respiratory infections, air pollution or other environmental exposures, although a specific trigger is not always identified. ## Warning signs requiring urgent assessment Severe or rapidly worsening breathlessness, inability to speak comfortably because of breathlessness, new confusion or drowsiness, bluish discoloration of the lips or skin, chest pain, collapse or signs of severe respiratory distress require urgent medical assessment. These features should not automatically be attributed to COPD. Other potentially serious conditions, including pneumonia, pulmonary embolism, pneumothorax and cardiac disease, may produce similar symptoms. ## Associated health problems People living with COPD have an increased risk of other health conditions, including cardiovascular disease, lung cancer, respiratory infections, osteoporosis, muscle weakness, anxiety and depression. These conditions can contribute to symptoms and functional limitation and should be considered during clinical assessment. ## Clinical reminder Symptoms alone do not confirm COPD. Persistent respiratory symptoms should prompt an appropriate clinical assessment, including consideration of exposure history, alternative diagnoses and spirometry where available.

## Overview COPD develops through a complex interaction between long-term exposure to harmful particles or gases, individual susceptibility and factors that affect lung development and function throughout life. These influences can cause persistent airway inflammation, small-airway abnormalities and destruction of alveolar tissue. Tobacco smoking is a major risk factor, but COPD also occurs in people who have never smoked. Household air pollution, occupational exposures and outdoor air pollution are important contributors, particularly in settings where exposure to smoke from solid fuels is common. ## Major causes and exposures ### Tobacco smoke Exposure to tobacco smoke is a major cause of COPD. Risk is associated with cumulative exposure and may involve active smoking and second-hand smoke. Tobacco smoke contributes to airway inflammation, mucus production, small-airway damage and destruction of lung tissue. ### Household air pollution Smoke produced by burning biomass fuels, coal and other solid fuels for cooking or heating can expose people to harmful particles and gases. Poor ventilation may increase exposure. Household air pollution is an important COPD risk factor in many low- and middle-income countries. ### Occupational exposure Long-term exposure to workplace dusts, chemical substances, fumes and vapours may contribute to COPD. Relevant exposures depend on the occupation and working environment. ### Outdoor air pollution Exposure to ambient particulate matter and other air pollutants may contribute to the development and progression of chronic respiratory disease. ## Individual and developmental risk factors Factors that may increase susceptibility to COPD include: - Alpha-1 antitrypsin deficiency, an inherited condition associated with an increased risk of early-onset emphysema. - Impaired lung development or reduced maximum lung function achieved during early adulthood. - Premature birth and low birth weight. - Recurrent or significant respiratory infections during childhood. - Asthma and other respiratory conditions, which may contribute to abnormal lung-function development or persistent respiratory impairment. - Family history and genetic susceptibility. These factors do not mean that an individual will inevitably develop COPD. Risk depends on the combination of exposures, susceptibility and life-course influences. ## How COPD develops Harmful exposures can trigger chronic inflammation and structural changes in the lungs. These may include: - Narrowing and remodelling of small airways. - Increased mucus production and impaired mucus clearance. - Destruction of alveolar walls, producing emphysema. - Loss of elastic recoil and reduced ability to empty the lungs efficiently. - Air trapping and lung hyperinflation. The relative contribution of airway disease and emphysema varies between individuals. ## Important distinction Chronic bronchitis is a clinical syndrome characterised by chronic cough and sputum production, while emphysema describes structural destruction of alveolar walls. Both may occur in people with COPD, but neither term alone fully describes every form of COPD. COPD is not itself an infectious disease. Respiratory infections can trigger exacerbations, but bacteria and viruses should not be listed as the underlying pathogens responsible for COPD. ## Prevention Reducing exposure to tobacco smoke, improving household ventilation and access to cleaner cooking fuels, controlling workplace exposures and reducing air pollution are important prevention measures. Protecting lung health throughout childhood and adulthood may also reduce future risk.

## Overview COPD should be considered in people with persistent respiratory symptoms, particularly breathlessness, chronic cough or sputum production, who have a history of exposure to relevant risk factors. Diagnosis requires integration of the clinical history, examination and objective assessment of lung function. Spirometry is the principal test used to demonstrate persistent airflow obstruction. A clinical diagnosis should not be based on symptoms, exposure history or a lung-function result in isolation. ## Clinical history The assessment should establish: - Onset, duration and progression of breathlessness. - Presence and duration of cough and sputum production. - Wheezing, chest tightness and exercise limitation. - Current and previous tobacco use, including cumulative exposure where possible. - Exposure to biomass-fuel smoke, household air pollution, occupational dusts, fumes and chemicals. - Previous respiratory infections and episodes of acute symptom worsening. - Previous diagnosis of asthma or other respiratory conditions. - Family history of COPD or inherited conditions such as alpha-1 antitrypsin deficiency. - Relevant comorbidities and their effect on symptoms and daily function. ## Physical examination Examination may reveal prolonged expiration, wheezing, reduced breath sounds, hyperinflation or use of accessory respiratory muscles. In more advanced disease, findings may include reduced body weight, peripheral muscle wasting, cyanosis or peripheral oedema. Physical examination findings vary and may be normal in early disease. They cannot independently confirm or exclude COPD. ## Spirometry Spirometry is essential for confirming persistent airflow obstruction in a person with a compatible clinical history. The GOLD diagnostic criterion uses a post-bronchodilator FEV₁/FVC ratio below 0.70 to demonstrate persistent airflow obstruction in the appropriate clinical context. - **FEV₁:** Forced expiratory volume in one second; the volume of air forcibly exhaled during the first second of the manoeuvre. - **FVC:** Forced vital capacity; the total volume of air forcibly exhaled after a full inspiration. - **FEV₁/FVC:** The proportion of the forced vital capacity exhaled in the first second. Spirometry should be performed using appropriate technique and acceptable-quality measurements. A borderline or discordant result may require repeat testing or further investigation, particularly when the clinical history strongly suggests COPD. ## Additional investigations Depending on the presentation and clinical question, investigations may include: - **Chest X-ray:** Helps assess alternative diagnoses and associated abnormalities. It does not independently confirm COPD. - **Chest CT:** May identify emphysema, bronchiectasis, lung nodules or other structural abnormalities when clinically indicated. - **Pulse oximetry:** Assesses peripheral oxygen saturation and may identify patients who need further evaluation. - **Arterial blood gas analysis:** May be indicated in selected patients with severe disease, suspected respiratory failure or significant hypoxaemia. - **Full blood count:** May help identify anaemia, polycythaemia or other contributing conditions. - **Alpha-1 antitrypsin testing:** Considered according to clinical history, age, family history and relevant guideline recommendations. - **Additional pulmonary function testing:** Lung volumes and diffusing capacity may help characterise physiological impairment when needed. ## Differential diagnosis Conditions that may resemble or coexist with COPD include: - Asthma. - Heart failure. - Bronchiectasis. - Tuberculosis and its respiratory sequelae. - Lung cancer. - Interstitial lung disease. - Pulmonary embolism. - Other causes of chronic cough or breathlessness. Asthma and COPD may share symptoms, and some individuals have features of both. Clinical history, disease pattern, exposure history and objective testing help guide the distinction. ## Assessing disease impact After diagnosis, assessment should extend beyond the FEV₁/FVC ratio. It should consider: - Degree of airflow obstruction. - Breathlessness and overall symptom burden. - Exercise capacity and functional limitation. - Frequency and severity of previous exacerbations. - Hospital admissions. - Nutritional status and muscle function. - Comorbidities and health-related quality of life. GOLD uses a structured approach to guide assessment and treatment selection. The clinical assessment should be individualised and periodically reviewed. ## Diagnostic caution A post-bronchodilator FEV₁/FVC below 0.70 supports COPD-related airflow obstruction when the history is compatible. Spirometry alone does not establish the full clinical diagnosis. Results near diagnostic thresholds should be interpreted carefully, and repeat testing or further evaluation may be appropriate.

## Overview COPD is a chronic condition that currently has no cure, but appropriate treatment can improve symptoms, exercise tolerance and quality of life, reduce exacerbations and help prevent further avoidable harm. Management should be individualised according to symptoms, exacerbation history, lung-function findings, comorbidities, treatment response, patient preferences and access to care. ## 1. Smoking cessation and exposure reduction Stopping tobacco use is a central component of COPD management. Support may include behavioural counselling and evidence-based smoking-cessation interventions. Patients should also be supported to reduce exposure to: - Second-hand tobacco smoke. - Smoke from biomass fuels and other solid fuels. - Occupational dusts, fumes and chemical irritants. - Outdoor air pollution where feasible. Improving ventilation and using cleaner household energy sources can help reduce exposure to harmful indoor air pollutants. ## 2. Pharmacological treatment ### Inhaled bronchodilators Inhaled bronchodilators are central to symptom management. They relax airway smooth muscle and improve airflow. The main groups include: - **Short-acting bronchodilators:** May be used for rapid symptom relief. - **Long-acting beta₂-agonists (LABAs):** Provide sustained bronchodilation. - **Long-acting muscarinic antagonists (LAMAs):** Reduce cholinergic bronchoconstriction and provide sustained bronchodilation. Long-acting bronchodilators may be used individually or in combination, depending on symptoms, exacerbation history and clinical assessment. ### Inhaled corticosteroids Inhaled corticosteroids are not automatically required for every person with COPD. They may be considered in selected patients, particularly where exacerbation history and blood eosinophil measurements indicate a greater likelihood of benefit. Potential benefits must be balanced against adverse effects, including an increased risk of pneumonia in some patients. ### Combination inhalers Some patients may benefit from combinations of long-acting bronchodilators, or from combinations that include an inhaled corticosteroid. The appropriate combination should be determined through individual clinical assessment and review of treatment response. ### Other medicines Additional treatments may be considered for selected patients according to their clinical phenotype, exacerbation pattern and comorbidities. Antibiotics are not routinely indicated for stable COPD and should be used only when clinically justified. No single inhaler combination or medication regimen is appropriate for every patient. ## 3. Pulmonary rehabilitation and physical activity Pulmonary rehabilitation combines exercise training, education and behaviour-change support. It can improve exercise capacity, symptoms and health-related quality of life. Patients should be encouraged to remain physically active within their functional abilities. Exercise plans should take account of disease severity, comorbidities and individual safety considerations. ## 4. Vaccination and infection prevention Vaccination helps reduce the risk of respiratory infections that may cause serious illness or trigger exacerbations. Vaccination recommendations should follow current national guidance and consider age, previous immunisation, comorbidities and local availability. Hand hygiene, avoiding respiratory infection exposure where feasible and timely assessment of worsening symptoms are also important. ## 5. Nutrition and supportive care Nutritional assessment is important because COPD may be associated with weight loss, muscle wasting or obesity. Support should be tailored to nutritional status and individual needs. Management may also include psychological support, assessment of anxiety and depression, and assistance with activities of daily living. ## 6. Oxygen and ventilatory support Long-term oxygen therapy may benefit carefully selected patients with chronic severe resting hypoxaemia. It should not be prescribed solely because a person feels breathless; eligibility requires appropriate clinical assessment and objective testing. Non-invasive ventilation may be appropriate in selected patients with acute or chronic hypercapnic respiratory failure, depending on the clinical circumstances. ## 7. COPD exacerbation management An exacerbation is an acute worsening of respiratory symptoms beyond usual day-to-day variation. Management depends on severity and may involve: - Assessment of respiratory distress, oxygenation and possible alternative diagnoses. - Short-acting inhaled bronchodilators. - Systemic corticosteroids when clinically indicated. - Antibiotics when indicated by the clinical presentation and applicable guidance. - Controlled oxygen therapy in patients who require oxygen, with appropriate monitoring. - Non-invasive ventilation for selected patients with acute hypercapnic respiratory failure. Severe exacerbations may require hospital assessment or admission. Treatment decisions should be made by qualified clinicians and guided by current recommendations. ## 8. Long-term monitoring and follow-up Regular review should assess: - Breathlessness, cough and sputum symptoms. - Exacerbations and hospital admissions since the previous visit. - Inhaler technique, adherence and treatment effectiveness. - Adverse effects and treatment burden. - Smoking status and ongoing exposure risks. - Vaccination status. - Exercise capacity, physical activity and nutritional status. - Comorbidities, mood and quality of life. - Need for oxygen assessment, pulmonary rehabilitation or additional support. An individualised self-management and exacerbation action plan can help patients recognise deterioration and understand when to seek medical attention. ## 9. Patient education Education should address the chronic nature of COPD, the purpose of prescribed medicines, correct inhaler use, avoidance of harmful exposures, physical activity, vaccination and recognition of exacerbations. Patients should be advised to seek urgent medical care for severe or rapidly worsening breathlessness, confusion, cyanosis, collapse or other signs of respiratory distress. ## Clinical reminder COPD management is long-term and individualised. Treatment should be reviewed as symptoms, exacerbation risk, lung function, comorbidities and patient circumstances change. This educational content does not replace clinical assessment or an individual treatment plan.