Pulmonary function tests (PFTs) are noninvasive tests that show how well the lungs are working. PFT involves a machine with mouthpiece where you will be asked to blow air as much as possible and suck that air back. This test measures lung volume, capacity, rate of flow, and gas exchange.

PFT generally diagnose obstructive airway disease and restrictive airway disease

It is advisable to do PFT when you are suffering from:

• Allergies
• Respiratory infections
• Trouble breathing
• Asthma
• Occupational lung disease
• Chronic smokers