Spirometry

What it is and how it works: Spirometry is a common test used to diagnose and monitor conditions that affect the lungs. It does this by assessing how well your lungs work when breathing in and out. It is performed by using a device called a spirometer, which is connected by a cable to a mouthpiece. During the test, a soft clip will be placed on your nose to prevent any air from escaping. You will then be asked to breathe in as much as possible and to breathe out into the mouthpiece. The test will normally be repeated at least three times to ensure a reliable result. Usually, the test takes about 30 to 90 minutes. 

What it detects: Spirometry can be used to diagnose and monitor asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis, and pulmonary fibrosis.