Spirometry

Spirometry measures the amount of air a person can breathe in and out as well as the speed of air movement to and from the lungs. Several different maneuvers are usually performed:

The Forced Vital Capacity (FVC) requires you to take a deep breath and blow into a tube as hard and long as you can (like blowing a trumpet.) This is a sensitive test for obstructive lung disease like asthma or emphysema. The Maximal Voluntary Ventilation (MVV) requires you to huff and puff through a mouthpiece, breathing as much as you can for about 10 seconds. This procedure measures lung flexibility and muscle strength.

These procedures are usually repeated several times after a short rest, to assure consistency and accuracy.  These tests take only a few minutes each, and may be repeated after the use of an inhaled medication (bronchodilator) to test for the presence of asthma.