Symptoms of comorbidities can overlap symptoms of
COPD and limit the applicability, effectiveness and safety of symptom-based COPD self-treatment guidelines, which have otherwise proven to be effective in patients with COPD without severe comorbidities. The use of symptom-based COPD action plans in such complex patients can therefore
lead to initiation of incorrect actions and/or delay of proper treatment (e.g. dyspnoea and chest pain can relate to both COPD and cardiovascular diseases). In addition, exacerbations of COPD per se or their treatment may also lead to flare-ups of comorbid diseases (e.g. increased anxiety during an exacerbation and steroid-induced hyperglycaemia). Finally, comorbid symptoms can influence the use of
action plans (e.g. depressive symptoms can recude treatment adherence). For these reasons, the use of self-treatment training solely directed towards COPD is less applicable, and potentially dangerous, to the large numbers of patients with COPD and comorbidities.