Chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is a condition characterised by airflow obstruction, which is usually progressive, not fully reversible and does not change markedly over several months (1).

The Global Initiative for Chronic Obstructive Lung Disease (GOLD), in its 2024 report, defines COPD as:

“a heterogeneous lung condition characterized by chronic respiratory symptoms (dyspnea, cough, sputum production and/or exacerbations) due to abnormalities of the airways (bronchitis, bronchiolitis and/or alveoli (emphysema) that cause persistent, often progressive, airflow obstruction” (2).

Airflow obstruction in COPD is caused by a combination of small airway disease (which increases airway resistance) and parenchymal damage (emphysema, that reduces the normal elastic recoil of lung parenchyma).

• relative contributions of these two changes varies from person to person and do not always occur together, but evolve at different rates over time (2)
• chronic inflammation of the airways results in structural changes, narrowing of small airways, luminal exudates in the small airways and destruction of the lung parenchyma.
  • these changes lead to loss of alveolar attachments to the small airways and decrease lung elastic recoil which in turn diminishes the ability of the airways to remain open during expiration
• loss of small airways may also contribute to airflow obstruction and mucociliary dysfunction (2)

COPD is an important cause of activity limitation in the population.

• approximately 1.2 million people have a diagnosis of chronic obstructive pulmonary disease (COPD) in the UK (1)
  • although there are 115,000 new diagnoses per year, most people with COPD are not diagnosed until they are in their fifties or older and many more people may remain undiagnosed
  • UK has the 12th highest recorded deaths from COPD in the world, with an age standardised mortality rate of 210.7 deaths per million people between 2001 and 2010

Reference:

1. National Institute for Health and Clinical Excellence (NICE) 2019. Chronic obstructive pulmonary disease: Management of chronic obstructive pulmonary disease in adults in primary and secondary care.
2. Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2024. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease