Chronic obstructive lung diseases are the most widespread destructive lung diseases in the world. It is predicted that, in the year 2020, COPD will be the third most frequently occurring disease in the world [WHO, 2011].

Typical for COPD are, for example, the progressive and partly irreversible deterioration in airflow (ventilation obstruction), the loss of alveolar septa, the impairment of the gas exchange capacity, loss of elasticity of the lung and formation of pulmonary hypertension well into advanced stages of the disease. Medication can help to alleviate symptoms and avoid progression of the disease, while there is currently no cure for COPD. At the present time, only the BOLD study gives information on the prevalence of COPD in Germany, but there are currently no adequate epidemiological data available.

The pathogenetic, molecular mechanisms underlie different COPD phenotypes, most of which are unknown. There is therefore also a lack of specific therapeutic approaches. The prognosis for patients is crucially influenced by the extrapulmonary pathological conditions. The assumption that the inflammation processes pass from the lung into the body circulation, is possibly based on a single critical event. On the other hand, reduced physical activity, which is considered a significant consequence of COPD, can possibly also contribute immensely to systemic inflammation.

It is thought that the phenotypingof COPD with regard to the clinical manifestion, physiology and morphology as well as to both the local and systemic inflammation processes, will lead to the achievement of a better understanding of the disease mechanisms and development of differentiated therapeutic approaches. In addition, phenotyping can possibly help to reveal overlaps between asthma and COPD phenotypes, that have recently been identified.