Inclusion Criteria:  Age >=18 years written informed consent IPF cohort: Documented history of IPF with definite or possible UIP pattern and signs of emphysema below 10% by HRCT (IPF diagnosis according to 2011 ATS/ERS IPF guidelines) COPD cohort: Documented history of COPD Stage II Group A or B, Stage III or IV, Group C or D (GOLD 2014)  Exclusion Criteria:  Long-term oxygen therapy Heart failure NYHA stages III and IV Left ventricular ejection fraction ≤ 45% Pregnancy and/or lactation Acute and/or life-threatening illness (instable angina pectoris, acute pulmonary arterial embolism, myocardial infarction, malignant tumor requiring treatment) Current drug or alcohol abuse Any medical, psychological or other condition impairing the patient's ability to provide informed consent IPF cohort: Acute exacerbation of IPF IPF cohort: Concomitant lung/airway diseases other than IPF (signs of emphysema >10% by HRCT) COPD cohort: Acute exacerbation of COPD COPD cohort: Concomitant lung/airway diseases other than COPD (e.g. Asthma bronchiale) Healthy cohort: Documented history of structural airway or lung disease