Smoking is the greatest risk factor for COPD, globally accounting for 46% of the contribution towards DALYs (disability-adjusted life years), but it can account for over 70% of COPD cases in high-income countries.[5,6]

Globally, the next most significant risk factors are air pollution from ambient particulate matter (20.7%) and occupational exposure to particulate matter, gases, and fumes (15.6%).[6]

A genetic factor is alpha-1 antitrypsin deficiency (AATD) occurring in 1-2% cases of COPD. Alpha-1 antitrypsin inhibits proteinase enzymes secreted by neutrophils in response to infection and irritants. People with AATD are predisposed to COPD and lung damage is made worse by smoking.[7,8]

Premature birth and low birth weight, childhood infections, childhood asthma, and lung damage from tuberculosis or HIV are also associated with increased risk of developing COPD.[7]

Being a progressive disease, COPD is the third leading cause of death worldwide, and the UK has one of the highest COPD death rates in Europe. More than 26,000 UK deaths in 2019 had COPD as the underlying cause, but numbers fell in 2020 (23,650 deaths) and 2021 (21,701 deaths) in part due to Covid-19 displacing COPD as the underlying cause of death in COPD patients.[5,9,10]