Lung function tests

This video explains what lung function tests are and how they are used to diagnose lung diseases, such as chronic obstructive pulmonary disease (COPD). Lung function tests are essential diagnostic tools used to assess respiratory health and assist in diagnosing various lung conditions. These tests can be performed at general practitioner (GP) clinics, specialist respiratory centres, and hospital-based clinics. However, due to COVID-19 restrictions, some GP clinics may not offer spirometry, requiring referrals to specialised facilities.

While lung function tests do not directly diagnose diseases, they provide crucial data that helps doctors determine conditions such as:

• Obstructive lung diseases (COPD, asthma, bronchiectasis)
• Restrictive lung diseases (interstitial lung disease, pulmonary fibrosis, asbestosis)
• Mixed lung conditions (e.g., asthma combined with pulmonary fibrosis)

Types of Lung Function Tests

Spirometry vs. Peak Flow Meter

• A peak flow meter measures the maximum speed of exhalation and is mainly used for asthma monitoring.
• Spirometry provides detailed lung function data, including total lung capacity and airflow limitations, making it more comprehensive for diagnosing COPD and other conditions.

Bronchial Provocation Test

• Used to assess asthma by administering inhaled substances to trigger airway reactions under controlled conditions.

Fractional Exhaled Nitric Oxide (FeNO) Test

• Measures airway inflammation to guide asthma and COPD treatment plans.

DLCO/Gas Diffusion Test

• Evaluates how efficiently oxygen is absorbed into the bloodstream, aiding in diagnosing conditions like COPD and pulmonary fibrosis.

Body Plethysmography

• Conducted inside an enclosed booth, this test determines lung volume and detects abnormalities in lung size.

If you’ve undergone a lung function test and need clarification, consult your GP or specialist to ensure you understand your results fully. Your GP or specialist doctor may order lung function tests to diagnose a lung disease and to monitor the progression of the lung disease and effectiveness of treatments.