By 2020, chronic obstructive pulmonary disease (COPD) will be the third cause of mortality. Extrapulmonary comorbidities influence the prognosis of patients with COPD. Tobacco smoking is a common risk factor for many comorbidities, including coronary heart disease, heart failure and lung cancer. Comorbidities such as pulmonary artery disease and malnutrition are directly caused by COPD, whereas others, such as systemic venous thromboembolism, anxiety, depression, osteoporosis, obesity, metabolic syndrome, diabetes, sleep disturbance and anaemia, have no evident physiopathological relationship with COPD. The common ground between most of these extrapulmonary manifestations is chronic systemic inflammation.

All of these diseases potentiate the morbidity of COPD, leading to increased hospitalisations and healthcare costs. They can frequently cause death, independently of respiratory failure. Comorbidities make the management of COPD difficult and need to be evaluated and treated adequately.