The study is based on the theory of a "unified airway" that considers the nose and paranasal sinuses together with lower airways as one integrated unit. The upper and lower respiratory tracts function as an interdependent physiologic mechanism, and stimuli that trigger changes in one portion of the airway, can provoke similar changes throughout the airway. This is well documented in asthmatic patients but documented poorly in patients suffering from chronic obstructive lung disease (COPD).

COPD is associated with sinonasal symptoms and decreased quality of life. Although nasal involvement has been found to directly affect the lower airway, sinonasal disease is under-diagnosed and under-treated in patients with COPD. This study is embedded in a larger project where the goal is to gain knowledge supporting the theory of a "unified airway" in patients with COPD.

Here sinonasal, pulmonary and generic health related quality of life will be studied in a group of patients with COPD versus a control group. The severity of nasal airway obstruction will be linked to the the severity of pulmonary airway obstruction. Assessment of pathological changes in the nose with nasal endoscopy, as well as performing a nasal cytological brushing for the identification of nasal inflammatory responses in the nose, will be conducted in both the control and study group.

Inclusion Criteria:

• Diagnosis of COPD: all stages
• Healthy individuals for the control group

Exclusion Criteria both groups:

• asthma
• systemic disease such as Cystic Fibrosis, Kartagener syndrome, sarcoidosis
• upper airway infection during the last 2 weeks
• COPD exacerbation during the last 6 weeks
• previous surgery in the nose and paranasal sinuses
• ongoing treatment for malignant disease
• severe depression, Alzheimers disease and Parkinson's disease
• pregnancy or nursing

patients diagnosed with chronic obstructive pulmonary disease (COPD) in St Olavs Hospital, Trondheim, Norway, and healthy participants matched in age and sex.

Biobank 1