Short answer: Spirometry is a breathing test: you blow out as hard and fast as you can into a mouthpiece, and the machine measures how much air you exhale and how quickly. The two main results are FEV1 (how much you blow out in the first second) and FVC (the total you can blow out). Their ratio, and how they compare with values predicted for your age, height and sex, help doctors assess asthma, COPD and other lung conditions.
At a glance
| What it is | You blow out as hard and fast as you can into a mouthpiece |
|---|---|
| FEV1 | How much you blow out in the first second |
| FVC | The total you can blow out |
| FEV1/FVC | The ratio that separates obstructive from restrictive patterns |
| % predicted | Your value compared with people of your age, height and sex |
| Keeping it | The values with the date, so changes over years are visible |
How it is done
You sit, wear a nose clip, take the deepest breath you can and blow out as hard and long as possible, usually three times or more. The test is often repeated 15–20 minutes after a reliever inhaler (bronchodilator) to see if the airways open. You may be asked to avoid some inhalers before the test.
What the report contains
| On the report | Unit | What it describes |
|---|---|---|
| FEV1 | litres and % predicted | air blown out in the first second |
| FVC | litres and % predicted | total air blown out after a full breath |
| FEV1/FVC ratio | % or decimal | the share of air blown out in the first second |
| PEF (peak flow) | L/min | the fastest flow during the breath |
| Post-bronchodilator values | change in mL and % | how much the results improve after an inhaler |
| Lower limit of normal (LLN) / z-score | — | statistical limits used in newer reports |
Results depend on effort and technique, so the report often comments on quality. Newer reports use z-scores and the lower limit of normal (from the GLI reference equations) rather than fixed percentages; your doctor explains which applies.
Keeping the report in your record
In Anpheros Daily you photograph the report or upload the PDF, and it goes into Documents under the person it belongs to, linked to the appointment it came from, next to the referral and the doctor's letter. On the Plus and Max plans "Read with AI" gives a plain-language summary and explains the terms, with the sentence each explanation came from marked; it stays labelled as AI, separate from what the specialist wrote. In the record the report is stored as an HL7 FHIR document, so you can share it with any doctor for a period you choose. Our guide on sharing your record with a clinic explains how.
What this page does not do
It explains what the investigation is and how its report is usually organised. It does not interpret your report or images, diagnose or recommend treatment. Reading the recording or images is the specialist's job; deciding what the report means for you is your doctor's.
Related pages
Sources
Frequently asked questions
What does FEV1/FVC mean?
The share of your total exhaled air that you blow out in the first second. A lower ratio suggests the airways are narrowed.
What does % predicted mean?
Your result compared with the expected value for someone of your age, height and sex.
Why is spirometry repeated after an inhaler?
To see whether the airways open with a reliever medicine, which helps doctors tell some conditions apart.
Can I take my inhaler before spirometry?
Ask the clinic. You may be asked to stop some inhalers for a few hours before the test.
Try it in Anpheros Daily
Keep your scan and test reports in one place in Anpheros Daily, ready to show at your next visit.
How it works in the app →
Anpheros builds a medical record that the patient controls and can share with any clinic, on an HL7 FHIR R4 platform, based in the EU. These guides help you understand and organise your health; they do not replace your doctor.
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