Lung capacity and a spirometer

During spirometry, you breathe into a mouthpiece connected to the device. The test records airflow and the amount of air moved during forceful breathing. It can help a clinician assess symptoms such as cough, wheeze or breathlessness and monitor a known breathing condition.

A result is interpreted with your symptoms, examination and medical history. It is not a complete picture of lung health and does not by itself name every possible cause. Some people repeat the blows several times, and a clinician may compare readings before and after a prescribed inhaler.

Wear comfortable clothing and follow the testing centre’s instructions about meals, smoking and medicines. Tell the clinician if you recently had a chest infection, feel unwell, have chest pain, or become dizzy with forceful breathing. Sit comfortably, seal your lips around the mouthpiece and follow each instruction closely.

A strong, complete effort is useful, but stop and tell the tester if you feel faint, develop pain or cannot continue. Ask when and how the result will be explained rather than trying to interpret a single reading alone.

Spirometry is usually planned rather than an emergency test. Seek urgent help for severe breathing difficulty, blue or grey lips, fainting, sudden chest pain or a sudden deterioration. After testing, report symptoms that do not settle when you rest.

Why do you recommend this test for me? Should I change any medicine beforehand, and when will we discuss what the result means for my care?