Pulmonary function tests are a group of tests that measure how well the lungs take in and release air and how well they move oxygen into the blood.
You will be asked to sit in a chair or in a clear plastic box that looks like a phone booth. You will wear nose clips so you only breathe through your mouthpiece. If you get tired, you can take breaks between the tests. The test can include
spirometry,
diffusion and/or
lung volumes.
- Spirometry: You take a deep breath and then blow it out hard and fast. Spirometry measures the force and the amount of air leaving the lungs. The test is repeated at least 3 times. You may be given an inhaler during this test.
- Diffusion: You take a deep breath and hold it for 10 seconds. The test measures how well your lungs move air into your blood.
- Lung Volumes: You breath in different mixtures of air. How much air you inhale and exhale is measured. The amount of air that stays in your lungs is also measured.
Bronchial Challenge Test
A bronchial challenge test is a medical test used to assist in the diagnosis of asthma. The patient breathes in nebulized drug - either methacholine or histamine. Thus the test may also be called a methacholine challenge test or histamine challenge test respectively. The drug provokes narrowing of the airways (bronchoconstriction). This is detected when the patient performs spirometry. People with asthma react to lower doses.