What is Spirometry?

Spirometry is a process which is used to measure lung function. It is one among a family of lung function tests which can be used in the diagnosis, monitoring, and treatment of disease. Spirometry tests are often ordered for people who have conditions linked to lung problems, or to rule out lung obstructions and other pulmonary issues in a diagnosis. For people who are researching spirometry because they need to go in for a test, it may be useful to know that the process is quick and totally painless.

The goal of a spirometry test is to measure the amount of air which can be exhaled from the lungs and inhaled into the lungs. Typically, the patient is asked to repeat a series of exercises three times, allowing the doctor to arrive at an average. For people who have never done a spirometry test before, the administrator may do a practice run in which values are not recorded so that the patient can get familiar with the process.

This test involves the use of a spirometer, a device which measures airflow. There are a number of different types of spirometers which can be used in spirometry. In all cases, the spirometer is attached to a tube which the patient will blow into during the testing.

In a classic spirometry test, the patient is asked to stand upright. A sterile tube will be fitted to reduce the spread of disease, along with a new mouthpiece. The patient's nose is often clipped shut so that no air can escape from the nose during the testing, and the patient may be asked to take several quiet breaths to relax before the test commences.

At a signal from the test administrator, the patient takes a deep breath, and then exhales forcefully, holding the exhalation for as long as possible. Then, the patient sharply inhales. The spirometer records the volume of air moved in and out of the lungs, and also the duration of the exhalation and inhalation. This data provides useful information about pulmonary function, including the peak flow, the high point of the graph.

Lung conditions like asthma and cystic fibrosis can be monitored with routine spirometry testing, and some patients use devices at home for intensive monitoring. Marked changes in spirometry results can indicate the presence of a problem which should be addressed before it gets worse. It is important for patients to cooperate with spirometry testing, since the results can be skewed if the patient does not follow directions.