Lung Function Testing


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Lung Function Testing


These simple, non-invasive tests are available in our specialist clinic. It evaluates how the lungs are functioning. It is useful in assessing patients with chronic cough, shortness of breath and in patients with history of long term cigarette smoking. We also use these tests to diagnose asthma, COPD and restrictive lung diseases. There are 3 components to pulmonary function testing: spirometry, lung volumes and diffusion capacity.


Spirometry is the most basic test. Spirometry measures how much air you can quickly breathe into and out from your lungs. This test is done by having you take a deep breath and blow hard into a tube connected to a machine. Most patients can perform this test easily in the outpatient setting with coaching from a trained technician. Sometimes a methacholine challenge test is done to check for hypersensitivity of the airway. Spirometry is useful to diagnose COPD and asthma.

Lung volumes 

Lung volumes measures how much air your lungs can hold, and there are two ways for the measurement to be done- the nitrogen washout technique and the body plethysmography technique. Lung volumes are useful to assess restrictive lung diseases like pulmonary fibrosis, muscular weakness, and chest wall deformity.

Diffusion capacity

Diffusion capacity measures how well your lungs put oxygen into and remove carbon dioxide from your blood. It involve breathing in a very small amount of carbon monoxide and measuring the amount that is transferred from the alveoli to the capillary. This test is useful to follow up lung fibrosis. Lung scarring and pulmonary hypertension.

See condition on chronic cough and COPD