Spirometry is used to assess how well your lungs are functioning by measuring how much air you inhale, how much you exhale and how quickly you exhale. Spirometry is used to diagnose asthma, chronic obstructive pulmonary disease (COPD) and other conditions that affect breathing.
You need to avoid strenuous activities for 30 minutes before the test. Abstain from drinking alcohol or smoking within four hours of the test. Avoid eating a big meal for two hours before the test. Ensure that you wear loose clothing.