What should you know about a spiro test for asthma?

You breathe into a mouthpiece connected to a spirometer. The device records how much air you exhale and how forcefully it leaves your lungs. The clinician may repeat the test after an inhaled medicine to see whether airflow changes. A result is interpreted with your pattern of symptoms, examination, and other possible explanations for breathlessness or cough; one reading does not describe every day.

Wheezing, chest tightness, and cough can occur with asthma, but they can also have other causes. Allergic rhinitis, house dust mite allergy, and chronic cough may be relevant when your clinician reviews the whole picture.

Follow the clinic's instructions about inhalers, meals, smoking, and exercise before testing. Wear comfortable clothing, sit or stand as directed, seal your lips around the mouthpiece, and give a full, strong blow when asked. Several attempts are normal because reliable results depend on technique. Tell the clinician if you feel dizzy, develop chest discomfort, or cannot continue.

Seek urgent medical help for severe breathlessness, blue or grey lips, confusion, fainting, or difficulty speaking in full sentences. Do not wait for a spirometry appointment during rapidly worsening breathing symptoms. A nebuliser treatment may be used by healthcare professionals in an acute setting when clinically appropriate.

Ask what the measured airflow shows, whether you should change any inhaler before a repeat test, and what symptoms should prompt urgent help.