Tests to measure your breathing

What are breathing tests?

Breathing tests measure how well your lungs are working. These tests are used to find the cause of problems such as feeling out of breath. They are sometimes called lung function tests.

Breathing tests measure things like:

• how much air you can take into your lungs
• how quickly you can blow air out of your lungs
• how well your lungs can take up oxygen
• the strength of your breathing muscles

Your results are compared to what would be expected in healthy people of your age, height, sex and ethnicity.

Your body mass index or BMI

Your health care professional may also weigh you to calculate your body mass index (BMI). This is a way of measuring whether you’re a healthy weight for your height.

Being overweight or underweight can affect your breathing, lung function and general health. Being overweight can cause breathlessness.

Your health care professional will also compare your results with any earlier test results, to track your progress.

Tests include:

• peak flow test
• spirometry and bronchodilator responsiveness (reversibility) test
• lung volume measurement
• gas transfer test
• respiratory muscle strength
• exhaled carbon monoxide levels
• fractional exhaled nitric oxide testing (FeNO)
• bronchial challenge tests