Co-morbidities occur frequently in patients with chronic obstructive pulmonary disease (COPD). Moreover, recent studies identified clusters of multi-morbidity in patients with COPD. Whether and to what extent multi-morbidity is COPD-specific remains currently unknown. Therefore, we would like to study the prevalence of multi-morbidity in subjects with and without COPD. The UK Biobank data gives the opportunity to combine information on objective and self-reported morbidities. Moreover, the clinical impact of these multi-morbidity clusters have never been studied in COPD. This project will provide a better insight in the overlap of co-morbidities and their impact on clinically relevant outcomes, such as physical activity, medication use, hospital admission rate and mortality. This project requires baseline data on the full cohort for self-reported illnesses, lifestyle factors, blood pressure, arterial stiffness, body impedance measures and spirometry. Data on death and hospital admissions will be requested at a later date.