Airway disease such as tumours and asthma lead to lung injuries. Therefore, a better understanding of airway mechanics parameters is very important to avoid lung injuries in patients undergoing mechanical ventilation for treatment of respiratory problems in intensive-care medicine as well as pulmonary medicine. The objective of this study was to investigate the role of airway diseases such as asthma and tumours on airway mechanics parameters using coupled fluid–solid computational analysis. The results obtained indicate that both tumours and asthma greatly affect the airway mechanics parameters (airflow velocity increased by about 15% and the strains increased by about 40%). Strain results of this study highlight significant changes in levels of airway parameters, which may translate into higher health risk associated with airway tumours and the asthmatic airways. These results combined with optimization suggest that it is possible to develop mechanical ventilation protocols to avoid lung injuries in patients.