COPD

COPD encompasses emphysema (alveolar destruction) and chronic bronchitis (mucus hypersecretion and small-airway disease). The COPD-X guidelines (Lung Foundation Australia and TSANZ) are the principal Australian reference and should be the source of truth for clinical statements.

Definition

COPD is a heterogeneous lung condition characterised by chronic respiratory symptoms (dyspnoea, cough, sputum production, exacerbations) due to abnormalities of the airways (bronchitis, bronchiolitis) and/or alveoli (emphysema) that cause persistent, often progressive, airflow obstruction.

Diagnosis requires demonstration of post-bronchodilator FEV₁/FVC < 0.7 (or below the lower limit of normal — a z-score under −1.65, which the TSANZ 2026 primary-care standard requires in preference to the fixed 0.7 ratio, since that ratio over-diagnoses obstruction in older patients) in a patient with appropriate symptoms and risk factors.^1,2 Note that GOLD grades 1–4 remain defined by percentage of predicted FEV₁; that is disease staging, and is a separate question from grading the degree of impairment.

Pathophysiology

Chronic exposure to noxious particles (most commonly tobacco smoke, but also biomass smoke and occupational dusts) drives chronic airway inflammation. Two main pathological processes are involved: emphysema (destruction of alveolar walls with loss of elastic recoil) and chronic bronchitis (mucus hypersecretion, goblet cell hyperplasia, and small-airway fibrosis). Most patients have features of both.

Co-morbidities

COPD is a systemic disease and co-morbidities drive outcomes as much as the airflow obstruction itself. Common co-morbidities include cardiovascular disease, lung cancer, osteoporosis, sarcopenia, metabolic syndrome, depression and anxiety, OSA, bronchiectasis, GORD, and frailty.

Prevalence

COPD affects approximately 1 in 13 Australians over 40 years of age and is the fifth leading cause of death in Australia. It is significantly under-diagnosed and is over-represented in Aboriginal and Torres Strait Islander people, in whom prevalence and mortality are markedly higher.

Causes

Tobacco smoking is the dominant risk factor in Australia. Other contributors include occupational exposure to dusts, fumes and chemicals (mining, construction, welding, agriculture), biomass smoke, air pollution, recurrent childhood respiratory infections, asthma, low birth weight and lung-development insults, and genetic factors — most notably alpha-1 antitrypsin deficiency.

Symptoms

The cardinal symptoms are progressive dyspnoea (initially on exertion), chronic cough, and sputum production. Wheeze, chest tightness, fatigue, and exercise limitation are common. Many patients normalise their breathlessness for years before presenting, and symptom burden often correlates poorly with FEV₁.

GOLD groups and Australian COPD-X classification

COPD severity is characterised by combining lung function (FEV₁ percent predicted), symptom burden (mMRC, CAT) and exacerbation history. GOLD groups A, B and E (formerly C and D) guide initial therapy. GOLD 2026 reframes COPD around disease activity — the ongoing burden of symptoms, exacerbations and progression — rather than static airflow limitation, so a stable FEV₁ does not by itself mean stable disease. It also lowers the exacerbation-risk threshold: a single moderate exacerbation (one requiring antibiotics and/or oral corticosteroids) is now sufficient to prompt escalation of therapy, where previously two or more events, or one hospitalisation, was the trigger.¹ The COPD-X guidelines (case-find, confirm diagnosis, optimise function, prevent deterioration, develop a plan, manage exacerbations) provide the Australian framework. These are guidelines, not rules — a clinician should still apply clinical judgement to the individual patient.

Diagnosis

Importance of a diagnosis

A formal diagnosis enables disease-modifying interventions (smoking cessation, pulmonary rehabilitation), appropriate pharmacotherapy, screening for treatable co-morbidities, and a written action plan. Early detection is associated with better outcomes.

How is it diagnosed?

Diagnosis is confirmed by post-bronchodilator spirometry demonstrating FEV₁/FVC < 0.7 (or below LLN) in a patient with relevant symptoms and exposures. Spirometry should be performed by a trained operator using quality-assured equipment.³

Radiology

Imaging is not required for diagnosis but is useful for excluding alternative diagnoses, identifying complications and characterising disease phenotype. HRCT may show centrilobular, panlobular (suggesting alpha-1 antitrypsin deficiency) or paraseptal emphysema, bronchial wall thickening, bullae, and co-existing bronchiectasis or fibrosis. CT is also used to assess suitability for lung volume reduction interventions and to screen for lung cancer in selected patients.

Lung function

Full lung function (spirometry, lung volumes, DLCO) characterises disease severity and identifies features such as hyperinflation, gas trapping (raised RV/TLC) and reduced gas transfer (low DLCO suggests emphysema). Six-minute walk testing assesses functional capacity and desaturation. Arterial blood gases are performed when chronic hypoxia or hypercapnia is suspected.

Sputum and microbiology

Routine sputum culture is not required but is recommended in patients with chronic sputum production, frequent exacerbations, suspected bronchiectasis overlap, or failure to respond to standard therapy. Common organisms include H. influenzae, S. pneumoniae, M. catarrhalis, and (in advanced disease) P. aeruginosa.

Investigations for related causes and co-morbidities

Alpha-1 antitrypsin level should be measured at least once in all patients diagnosed with COPD (per GOLD recommendations). Blood eosinophil count guides ICS use. Screening for cardiovascular disease, OSA, depression, and lung cancer (per Australian guidance) should be considered.

Management

Management and goals

Goals are to: reduce symptoms (breathlessness, exercise limitation, sputum), reduce exacerbation frequency and severity, improve health status and quality of life, slow disease progression, and reduce mortality.

Treatment options

Treatment is multimodal:

• Smoking cessation — the single most effective intervention.
• Pulmonary rehabilitation — strong evidence for all symptomatic patients.
• Inhaled therapies — LAMA, LABA and ICS (selective), guided by symptom burden, exacerbation risk and blood eosinophils.
• Vaccinations — influenza, pneumococcal, COVID-19, RSV and pertussis.
• Long-term oxygen therapy when criteria are met (resting PaO₂ ≤ 55 mmHg or SaO₂ ≤ 88%). This is a different number from the acute one: during an exacerbation, oxygen is titrated to a target SpO₂ of 88–92% because of the risk of hypercapnia.
• Non-invasive ventilation in selected patients with chronic hypercapnia.
• Lung volume reduction (surgical or bronchoscopic) and transplant assessment in advanced disease.
• Treatment of co-morbidities.
• Advance care planning in severe disease.^4,5,6,7

Identifying an exacerbation

An exacerbation is an acute worsening of respiratory symptoms — increased dyspnoea, cough, sputum volume or purulence — that warrants additional treatment. Severity is classified as mild (treated with SABD), moderate (requires antibiotics and/or oral corticosteroids), or severe (requires emergency department or hospital management).

Action plan

A written COPD action plan, individualised to the patient, includes baseline status, the “early-warning zone” triggering increased reliever use and a clinician contact, the “unwell zone” triggering oral corticosteroids and antibiotics as pre-supplied (where appropriate), and the “severe zone” requiring urgent medical attention.

Medications

Medications for COPD

Inhaled medications form the cornerstone of pharmacotherapy:

• Short-acting bronchodilators (SABA, SAMA) — for rescue.
• Long-acting muscarinic antagonists (LAMA) — first-line maintenance.
• Long-acting beta-2 agonists (LABA) — typically in combination.
• LAMA/LABA combinations.
• Triple therapy (LAMA/LABA/ICS) for patients who continue to exacerbate — a single moderate exacerbation is sufficient under GOLD 2026 — particularly with higher blood eosinophils.
• ICS-containing therapy — caution with risk of pneumonia; reserve for those with exacerbations and an eosinophilic phenotype.
• Oral roflumilast in severe chronic bronchitis with frequent exacerbations.
• Azithromycin for selected frequent exacerbators.
• Mucolytics (e.g. N-acetylcysteine) in chronic bronchitis.

Correct use of medications

Inhaler technique is the strongest determinant of medication effectiveness. Device selection should match patient capability (inspiratory flow, dexterity, cognition). Technique should be demonstrated, verified, and re-checked at every encounter. The Lung Foundation Australia provides patient-facing device videos.

Order of medications

For routine use:

1. Bronchodilator first (especially before exertion or airway clearance)
2. Airway clearance if there is significant sputum
3. ICS (if prescribed) with mouth rinse afterwards
4. Oral medications with appropriate meal timing per prescriber instructions

Multi-system manifestations

Cardiovascular disease

CVD is the leading cause of death in mild–moderate COPD. Patients should have cardiovascular risk assessed and modifiable risk factors aggressively treated. Beta-blockers are not contraindicated in COPD; cardio-selective agents are preferred.

Osteoporosis and sarcopenia

Bone disease and muscle wasting are common, driven by inflammation, inactivity, corticosteroid use, and malnutrition. DXA screening, vitamin D and calcium, resistance training, and pharmacotherapy where indicated are core management.

OSA and lung cancer

The “overlap syndrome” of COPD plus OSA has worse outcomes than either alone; OSA should be actively screened for. COPD is a strong risk factor for lung cancer; targeted screening by low-dose CT is now recommended in Australia for eligible high-risk patients (the National Lung Cancer Screening Program commenced in 2025).

Anxiety, depression and cognitive impairment

Depression and anxiety are highly prevalent and contribute to dyspnoea, reduced activity, and worse outcomes. Screening and integrated mental health support are part of high-quality COPD care. Cognitive impairment is also more common in advanced COPD.

Living with COPD

Nutrition

Both underweight and overweight states are problematic. Cachexia and sarcopenia (reduced fat-free mass) predict poor outcomes. Smaller, more frequent meals reduce post-prandial breathlessness. Dietitian input is valuable when weight or muscle mass changes.

Sleep

Sleep is frequently disturbed by cough, breathlessness, and nocturnal hypoxaemia or hypercapnia. OSA should be screened for. In selected patients with chronic hypercapnia, nocturnal non-invasive ventilation improves outcomes.

Travel

Most patients with COPD can travel. Considerations include carrying medications and prescriptions, a clinician letter, action plan, and an assessment for in-flight oxygen if resting SpO₂ is <92–95%, FEV₁ <50% predicted, or there is a recent exacerbation. Hypoxic challenge testing can guide oxygen needs.

Prognosis

Prognosis depends on age, FEV₁, exacerbation frequency, BMI, dyspnoea (mMRC), exercise capacity (6MWT), and co-morbidities. The BODE index integrates these and predicts mortality. Smoking cessation, pulmonary rehabilitation, and optimal inhaled therapy are the interventions with the greatest effect on outcome.

Anxiety, depression and palliative care

A palliative approach is appropriate alongside disease-modifying treatment in advanced COPD, addressing breathlessness, fatigue, and existential distress. Advance care planning should be a routine conversation, not reserved for the end of life.

Role of the physiotherapist

For selected people with severe, uneven emphysema and marked hyperinflation, a specialist team may also consider bronchoscopic lung volume reduction with endobronchial (Zephyr) valves — a pathway in which pulmonary rehabilitation before and after the procedure is a prerequisite, not an add-on.

Physiotherapy is central to living well with COPD. The cardiorespiratory physiotherapist delivers and supervises pulmonary rehabilitation — the exercise-based programme with the strongest evidence for reducing breathlessness and improving quality of life — and teaches breathing retraining, pacing and energy conservation to manage breathlessness day to day. Where there is sputum, they prescribe and review airway clearance and check inhaler technique at every visit. They also support self-management: recognising a flare-up early, using an action plan, and staying active through and after exacerbations.^{8,9,10,11,12,13}

Warning signs

Part 1 · References

1. Global Initiative for Chronic Obstructive Lung Disease. Global strategy for the diagnosis, management and prevention of COPD: 2026 report. GOLD; 2026. Available at: goldcopd.org
2. Thoracic Society of Australia and New Zealand. SPC01: TSANZ Technical Standards for Spirometry in Australian Primary Care. TSANZ; 2026.
3. Yang IA, George J, McDonald CF, et al. The COPD-X Plan: Australian and New Zealand guidelines for the management of chronic obstructive pulmonary disease. Version 2.78. Brisbane: Lung Foundation Australia and Thoracic Society of Australia and New Zealand; October 2025. Available at: copdx.org.au
4. Anthonisen NR, Connett JE, Kiley JP, et al. Effects of smoking intervention and the use of an inhaled anticholinergic bronchodilator on the rate of decline of FEV1: the Lung Health Study. JAMA 1994;272(19):1497–1505.
5. Long-Term Oxygen Treatment Trial Research Group. A randomized trial of long-term oxygen for COPD with moderate desaturation. N Engl J Med 2016;375(17):1617–1627.
6. Nocturnal Oxygen Therapy Trial Group. Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: a clinical trial. Ann Intern Med 1980;93(3):391–398.
7. Osadnik CR, Tee VS, Carson-Chahhoud KV, Picot J, Wedzicha JA, Smith BJ. Non-invasive ventilation for the management of acute hypercapnic respiratory failure due to exacerbation of chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2017;(7):CD004104.
8. McCarthy B, Casey D, Devane D, Murphy K, Murphy E, Lacasse Y. Pulmonary rehabilitation for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2015;(2):CD003793.
9. Puhan MA, Gimeno-Santos E, Cates CJ, Troosters T. Pulmonary rehabilitation following exacerbations of chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2016;(12):CD005305.
10. Holland AE, Mahal A, Hill CJ, et al. Home-based rehabilitation for COPD using minimal resources: a randomised, controlled equivalence trial. Thorax 2017;72(1):57–65.
11. Osadnik CR, McDonald CF, Jones AP, Holland AE. Airway clearance techniques for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2012;(3):CD008328.
12. Gosselink R, De Vos J, van den Heuvel SP, Segers J, Decramer M, Kwakkel G. Impact of inspiratory muscle training in patients with COPD: what is the evidence? Eur Respir J 2011;37(2):416–425.
13. Holland AE, Hill CJ, Jones AY, McDonald CF. Breathing exercises for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2012;(10):CD008250.

References are numbered in citation order (Vancouver/BMJ style) and were current at the time of writing. Guidelines are living documents — verify against the latest version before clinical use.