Spirometry is the most common of the pulmonary function tests (PFTs), measuring lung function, specifically the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. Spirometry is an important tool used for generating pneumotachographs, which are helpful in assessing conditions such as asthma, pulmonary fibrosis, cystic fibrosis, and COPD.
Spirometry is indicated for the following reasons:
to diagnose or manage asthma;
to detect respiratory disease in patients presenting with symptoms of breathlessness, and to distinguish respiratory from cardiac disease as the cause;
to measure bronchial responsiveness in patients suspected of having asthma;
to diagnose and differentiate between obstructive lung disease and restrictive lung disease;
to follow the natural history of disease in respiratory conditions;
to assess of impairment from occupational asthma;
to identify those at risk from pulmonary barotrauma while scuba diving;
to conduct pre-operative risk assessment before anaesthesia or cardiothoracic surgery;
to measure response to treatment of conditions which spirometry detects;
to diagnose the vocal cord dysfunction.