COPD (Chronic Obstructive Pulmonary Disease): A Complete Guide

Chronic obstructive pulmonary disease (COPD) is a common, preventable, and treatable disease characterised by persistent respiratory symptoms and airflow limitation. It is a leading cause of morbidity and mortality in the UK. This guide is aligned with NICE guideline NG115 (2019, updated 2022) and the Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy.

Key Facts

Approximately 1.2 million people are diagnosed with COPD in the UK; an estimated 3 million more are undiagnosed
COPD is the second most common cause of emergency hospital admission in the UK
Smoking is responsible for approximately 90% of COPD cases in the UK
COPD accounts for around 30,000 deaths annually in England and Wales
Spirometry is essential for diagnosis — clinical features alone are insufficient
Early diagnosis and treatment significantly improve quality of life and reduce exacerbation frequency

What is COPD?

COPD is an umbrella term covering conditions that cause obstructed airflow from the lungs — primarily emphysema (destruction of alveolar walls causing air trapping) and chronic bronchitis (chronic productive cough for three or more months per year for two consecutive years). Most patients have both components. The airflow limitation is typically progressive and driven by chronic inflammation in the airways in response to noxious particles or gases, most commonly from cigarette smoke. Unlike asthma, airflow obstruction in COPD is not fully reversible, and the disease is frequently under-recognised.

Risk Factors

Cigarette smoking is the principal risk factor for COPD, including passive smoke exposure. Other important risk factors include occupational exposure to dusts, fumes, and chemicals (implicated in approximately 15% of cases); indoor air pollution from biomass fuels; outdoor air pollution; recurrent lower respiratory tract infections in childhood; alpha-1 antitrypsin (AAT) deficiency (a genetic cause accounting for 1–2% of cases); and lower socioeconomic status with compounding exposures.

Symptoms and Clinical Features

COPD typically presents in smokers or ex-smokers over 35 years with progressive breathlessness on exertion, chronic productive cough, and wheeze. Onset is insidious and patients often attribute breathlessness to ageing, delaying presentation. NICE recommends considering a COPD diagnosis in patients over 35 who smoke or have smoked and present with exertional breathlessness, chronic cough, regular sputum production, or frequent winter bronchitis, with no features suggesting an alternative diagnosis.

CAT Score: The COPD Assessment Test (CAT) is a validated 8-item questionnaire quantifying COPD impact on daily life (score 0–40). A score of 10 or above indicates high impact and warrants management review. The MRC dyspnoea scale (grades 1–5) is also widely used in UK practice. Both should be recorded at every COPD review appointment.

Diagnosis

Post-bronchodilator spirometry is the cornerstone of diagnosis. NICE defines COPD by a post-bronchodilator FEV1/FVC ratio below 0.70. Severity is graded by FEV1 as percentage of predicted: GOLD 1 (mild) ≥80%; GOLD 2 (moderate) 50–79%; GOLD 3 (severe) 30–49%; GOLD 4 (very severe) <30%. Additional investigations include CXR, FBC, BMI assessment, alpha-1 antitrypsin testing in early-onset or familial cases, CT thorax if malignancy or bronchiectasis is suspected, and pulse oximetry.

Differential Diagnoses: Conditions to exclude before diagnosing COPD include asthma (younger onset, atopy, significant reversibility, variable symptoms); cardiac failure (echocardiogram, BNP); bronchiectasis (CT features, copious purulent sputum); lung cancer (haemoptysis, weight loss, clubbing, unilateral signs); tuberculosis; and obliterative bronchiolitis. Asthma-COPD overlap (ACO) is increasingly recognised and may affect treatment decisions.

Stable COPD Management

Non-pharmacological interventions

Smoking cessation is the most effective intervention to slow COPD progression. NICE recommends offering all COPD patients who smoke referral to smoking cessation services and pharmacotherapy. Varenicline (Champix) is first-line; combination NRT and bupropion are alternatives. Pulmonary rehabilitation (PR) — at least six weeks of supervised exercise and education — is one of the most effective treatments available and significantly improves exercise capacity, quality of life, breathlessness, and hospital admission rates. NICE recommends PR for all patients with MRC grade 3 dyspnoea or above, or following a hospitalised exacerbation. Annual influenza vaccination and a one-off pneumococcal vaccination are recommended for all COPD patients. Advance care planning should be initiated in severe or very severe disease.

Pharmacological management

Short-acting bronchodilators (SABA — salbutamol 100 mcg; or SAMA — ipratropium 20 mcg) should be offered for as-needed use in all symptomatic patients. For those with persistent symptoms or moderate-to-severe obstruction, NICE recommends escalation to a long-acting muscarinic antagonist (LAMA — e.g., tiotropium 18 mcg daily via HandiHaler, or umeclidinium 62.5 mcg daily) or long-acting beta-2 agonist (LABA — e.g., salmeterol 50 mcg twice daily, formoterol 12 mcg twice daily, or indacaterol 150–300 mcg daily).

For persistent breathlessness or exercise limitation on monotherapy, combination LAMA/LABA therapy (e.g., umeclidinium/vilanterol [Anoro Ellipta] or tiotropium plus formoterol) is recommended. Inhaled corticosteroids (ICS) should not be routinely used in COPD. NICE recommends considering ICS (with LABA — e.g., fluticasone/salmeterol [Seretide] or budesonide/formoterol [Symbicort]) only in patients with FEV1 <50% predicted and two or more moderate or one severe exacerbation per year. Triple therapy (ICS/LABA/LAMA — e.g., fluticasone furoate/umeclidinium/vilanterol [Trelegy Ellipta]) is indicated in asthma-COPD overlap, persistent exacerbations, or blood eosinophil count ≥300 cells/µL despite dual therapy.

Theophylline may be considered as add-on therapy noting its narrow therapeutic window and multiple drug interactions. Carbocisteine (mucolytic) should be considered for chronic productive cough unresponsive to other interventions. Oral azithromycin 250 mg three times weekly may be considered for ex-smokers with three or more exacerbations per year despite optimised treatment — ECG (to exclude QTc prolongation), sputum culture, and audiometry are required first.

Acute Exacerbations of COPD

An acute exacerbation is defined as an acute worsening of respiratory symptoms beyond normal day-to-day variation requiring a change in medication. Exacerbations are often triggered by respiratory infections or pollutants, and are a major driver of hospitalisation and accelerated decline. Community management includes increased SABA frequency (salbutamol 2.5 mg nebulised or 4–8 puffs via spacer every 4–6 hours); oral prednisolone 30 mg daily for 5 days; antibiotics if sputum is purulent or there are signs of infection (amoxicillin 500 mg three times daily or doxycycline 100–200 mg daily for 5 days); and consideration of hospital-at-home schemes.

Indications for hospitalisation include severe breathlessness, rapid onset, cyanosis, acute confusion, SaO2 <90%, significant comorbidity, or failure to respond to community treatment. Controlled oxygen targeting SaO2 88–92% is essential — avoid uncontrolled high-flow oxygen. Non-invasive ventilation (NIV) with BiPAP is recommended for persistent hypercapnic respiratory failure (pH <7.35, PaCO2 >6 kPa) despite initial treatment, significantly reducing mortality and intubation rates.

Long-Term Oxygen Therapy (LTOT): NICE recommends assessing for LTOT in stable COPD patients with PaO2 ≤7.3 kPa on two ABG measurements taken 3 weeks apart when clinically stable. LTOT should be prescribed for at least 15 hours daily and improves survival in severe hypoxaemia. Patients with PaO2 7.3–8.0 kPa plus secondary polycythaemia, oedema, or pulmonary hypertension may also qualify. Assessment must be performed by a specialist respiratory service.

Monitoring and Follow-up

NICE recommends at least annual review for all COPD patients, more frequently in severe disease. Review should include spirometry (every 3 years in mild-moderate; annually in severe), CAT or MRC score, exacerbation frequency, inhaler technique and concordance, nutritional status, BMI, pulse oximetry, smoking status, vaccination status, medication review, and consideration of pulmonary rehabilitation or specialist referral.

Frequently Asked Questions

Can COPD be cured?

There is currently no cure for COPD. However, stopping smoking, using inhaled medications, completing pulmonary rehabilitation, and staying vaccinated can significantly slow progression, reduce symptoms, prevent exacerbations, and improve quality of life. Lung transplantation is considered in highly selected patients with end-stage disease.

I have never smoked — can I still develop COPD?

Yes. While smoking causes around 90% of UK COPD cases, non-smokers can develop COPD from occupational dust and fume exposure, indoor air pollution, frequent childhood chest infections, or alpha-1 antitrypsin deficiency. If you have persistent breathlessness or chronic cough and have never smoked, speak to your GP and ask about spirometry — COPD is often missed in this group.

What is pulmonary rehabilitation and how do I access it?

Pulmonary rehabilitation (PR) is an NHS-funded supervised programme of exercise training and education, typically delivered over 6–8 weeks, two to three times per week. It has strong evidence for improving breathlessness, fitness, mood, and reducing hospital admissions. Your GP or respiratory specialist can refer you. Home-based and online programmes are increasingly available for those unable to attend in person.

When should I go to hospital during a COPD flare-up?

Call 999 or go to A&E immediately if you experience severe breathlessness at rest, blue lips or fingertips, confusion or drowsiness, or your reliever inhaler is not working. Otherwise, contact your GP, use your COPD rescue pack if you have one, or call NHS 111 for guidance on safe home management.

What is a COPD rescue pack?

A rescue pack is a pre-prescribed home supply of oral steroids (prednisolone 30 mg for 5 days) and antibiotics (typically amoxicillin or doxycycline) to start at the first sign of a flare-up. NICE recommends rescue packs for patients with moderate-to-severe COPD who have had two or more exacerbations per year, accompanied by a written self-management plan explaining when and how to use them.