This page gives you information about the condition you are being assessed for and the processes carried out during the assessment.

About sleep apnoea

Obstructive Sleep Apnoea (OSA) is a condition where the walls of the throat relax and narrow during sleep, interrupting normal breathing.

There are 2 types of breathing interruption typical of OSA:


Where the muscles and soft tissues in the throat relax and collapse causing a total blockage of the airway. It is called an apnoea when the airflow is blocked for 10 seconds or more.


A partial blockage of the airway that results in an airflow reduction of more than 30% for 10 seconds or longer.

Many people with OSA experience episodes of both apnoea and hypopnoea. This condition is sometimes referred to as Obstructive Sleep Apnoea-Hypopnoea Syndrome (OSAHS).

The term ‘obstructive’ separates OSA from rarer forms of sleep apnoea, such as central sleep apnoea, which is caused by the brain not sending signals to the breathing muscles during sleep.

In the United Kingdom around 4 in every 100 middle-aged men and 2 in every 100 middle-aged women have OSA.

Although the condition can make you feel very tired it is one of the most easily treated. An overnight screening study will confirm whether you have OSA and if so, the severity of the condition.

Once the condition has been diagnosed, effective treatment can begin. This will help to ease the symptoms.

Symptoms of sleep apnoea

  • Loud snoring
  • Excessive daytime sleepiness
  • Feelings of choking or shortness of breath
  • Restless sleep
  • Unrefreshing sleep
  • Changes in personality
  • Morning headache
  • Partner worried by breathing pauses
  • Night time sweating
  • Recurrent insomnia
  • Nocturnal cough
  • Waking up to go to the toilet in the night

What to expect

Your assessment appointment will be at the new Gloucestershire Quayside Community Diagnostic Centre, Quay Street, Gloucester, GL1 2JN.

At your appointment for the overnight screening test the following will happen:

  • Your height, weight and collar size will be recorded.
  • You will be given an explanation of how to wear the equipment.
  • You will be asked to complete the Patient and Partner questionnaires and return them with the equipment.

There are 2 types of tests that we currently perform:

Overnight oximetry

This is a simple screening test which is usually performed at home. You will be given a simple to use machine to take home and wear while you are asleep.

This machine will measure the level of oxygen in your blood and your heart rate. When the machine is returned the information will be downloaded and analysed by a trained physiologist.

Multi-channel study

For this test you will be wearing a belt around your chest and abdomen which measures the effort of breathing. You will also need to wear a nasal cannula to measure the airflow through your nose and a pulse oximeter on your finger that records oxygen saturation and your heart rate.

The machine is pre-set to start and stop at specific times; however, please follow your normal bedtime routine.

If you wear nail polish or false nails please remove before your appointment as these will affect the quality of the recording.

Returning the equipment

Please return the equipment the following day as advised on collection. This should be before 10:30 am.

The equipment is issued to patients on a daily basis so must be returned the day after testing at the required times.


The information from the study will be downloaded, scored and analysed by a Physiologist along with your own and your partner’s questionnaires.

The Physiologist will then make a decision on the next step of the pathway for you.

They will write to you with the results of your sleep study and advise whether you need either a clinic appointment to discuss the results further or you will be offered of an appointment to start continuous positive airway pressure (CPAP) treatment.

Contact information

Lung Function Department

Cheltenham General Hospital

Tel: 0300 422 4313

Monday to Friday, 8:00am to 5:30pm

Further information

Printable version of this page

Sleep apnoea screening GHPI0948_04_24 Department: Respiratory Review due: April 2027 PDF, 290.3 KB, 4 pages
Reference number GHPI0948_04_24
Department Respiratory
Review due April 2027