Our intentions are to phenotype Chronic Obstructive Pulmonary Disease (COPD) patients on the basis of factors that a related to (a) exacerbation frequency which will include (b) lung function to assess disease severity, (c) baseline therapy, (d) airway and systemic inflammatory markers, (e) health status, (f) gene expression, (g) airway bacterial and viral load and (h) co-morbidity including cardiovascular disease, diabetes and psychological disease, (i) psychological factors,(j) mortality, (k) nasal susceptibility to rhinovirus infection, (l) heart rate variability (m) exhaled hydrogen sulphide.