Your heartbeat, blood pressure and oxygen levels will be checked throughout.

If you have false teeth, you will need to take them out.

Your nose and throat will be sprayed with a local anaesthetic – or you may be given a lozenge to suck. This will prevent any pain as the bronchoscope goes in.

You don’t need to be put to sleep for this test, but your doctor may offer you a mild sedative injection, especially if you are feeling anxious. It will make you feel drowsy and relaxed.

When you are ready, the doctor passes the bronchoscope into your nose or mouth, through the vocal chords and down into the windpipe and lung. This won’t hurt, but most patients say it is uncomfortable. You may feel as if you can’t catch your breath. Don’t worry – you aren’t going to choke. The feeling will pass, and once the bronchoscope is in place, the worst is over.

As the doctor puts the bronchoscope in, s/he may spray some more anaesthetic into your voicebox. This won’t hurt, but it might make you cough a little.

Don’t worry that you won’t be able to breathe. There is plenty of room around the bronchoscope for oxygen to reach your lungs. The doctor can also give you extra oxygen through a thin tube put into your nostril.

If your doctor needs to take some samples of lung tissue, this can be done easily and painlessly.

Occasionally the doctor may wash the lungs with sterile water. The water is then painlessly sucked back out of the lungs.

Once your doctor has finished the examination s/he will gently remove the bronchoscope, and the test is over.

All of this normally takes about 10-20 minutes.