A lung function test, also known as pulmonary function testing or spirometry, is a medical test used to assess how well your lungs are working.  A Spirometry Test measures the amount of air you can breathe in and out of your lungs, and how hard and fast you can breathe out. 

The aim of spirometry/pulmonary function test is to assess variability of airflow obstruction, and to measure the degree of airflow obstruction compared to predicted normal. Accurate measurement of respiratory function is necessary to assess and manage asthma and lung problems.

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