Spirometry (Lung Function Test)

Spirometry is a breathing test that measures how much air you can inhale and exhale, and how quickly you can exhale. It helps diagnose asthma, chronic obstructive pulmonary disease (COPD), and other lung conditions, and can monitor disease progression or treatment response.

• Avoid smoking, heavy exercise, or eating a large meal before the test.
• Your doctor may ask you to stop using certain inhalers or medications beforehand.
• Wear loose clothing for comfort.

You will breathe into a mouthpiece connected to a machine called a spirometer. The test involves taking deep breaths and forcefully exhaling several times. A technician will coach you through the process. The exam takes about 15–30 minutes.

• Spirometry is safe for most people.
• Some may feel lightheaded, dizzy, or short of breath during testing.
• Rarely, it can trigger coughing or an asthma attack in sensitive patients.

Results are usually available immediately. Your doctor compares your values to normal ranges and explains whether lung function is impaired. Additional tests may be ordered if needed.