The overlap between asthma and COPD: a case study

Asthma and chronic obstructive pulmonary disease (COPD) are the most common respiratory diseases routinely seen in primary care. In the UK, there are an estimated 8 million people with asthma, compared to approximately 1.2 million people with COPD. There are several clinical features that clearly distinguish them from one another (Table 1).¹ Asthma is characterised by chronic inflammation and hyper-responsiveness of the airways, leading to variable airflow limitation.² It is usually, but not always, diagnosed in childhood and patients typically experience intermittent wheeze, shortness of breath, chest tightness and cough, which improves either spontaneously or with treatment.³

COPD is an umbrella term for common disease presentations such as chronic bronchitis and emphysema.⁴ In contrast to asthma, COPD is a progressive disease with significant impact on mortality and morbidity.⁵ It is largely preventable, and most commonly caused by smoking, although other causes may be attributed.⁶ Patients with COPD typically experience persistent symptoms including breathlessness, reduced exercise tolerance, and increased production of mucus in the airways. This leads to chronic cough and susceptibility to infection, which may result in frequent exacerbations.⁷