The tests should take between 30 minutes and one hour. But if you are very breathless, they may take longer. You won’t be rushed through.

These are tests to see how well you efficient your breathing is.

When you arrive at the hospital, the tester will measure your weight and height. If they can’t measure your height (if you are in a wheelchair, for example), they will measure your arm span – this gives them a guide to your height.

For the tests, you will need to blow into a machine. With some machines, you blow into a tube; for others, you put a mouthpiece in your mouth, like a snorkel, and then blow. You will usually have to do this several times – but the tester will not rush you.

If you are breathing through your nose, and this is affecting your breathing test, you may be asked to wear a nose-clip.

If you wear dentures and they’re loose, then you might need to take them out when you blow into the machine.

Occasionally, the tester might ask you to sit in a booth, which looks a bit like a small see-through shower cubicle. The door will be closed and the test will be done while you sit inside. This will help your tester get more detailed results.

Spirometry

This measures your FEV1 – which is how much air you can expel from your lungs in the first second of breathing out. It also measures your FVC – which is how much air you can get into your lungs and how long it takes for you to empty your lungs.