Why might I need a sleep study?

When you are asleep your breathing can become weaker for several reasons.

If you snore heavily this may obstruct your airways and stop air from reaching your lungs. If this happens your breathing patterns may become irregular and affect your sleep quality, leading to daytime sleepiness. This condition is called obstructive sleep apnoea (OSA).

If you have chest problems, such as chronic bronchitis, scoliosis or muscle disorders, your breathing may also become too shallow during sleep. If this happens your carbon dioxide levels will rise and your oxygen levels fall.

What is a sleep study?

The most common kind of sleep study is called a "screening study". In this study we make overnight recordings of:

  • your oxygen levels (by attaching a small clip to your finger)

  • your breathing (by taping a small sensor between your nose and upper lip)

  • the movements of your chest and abdomen (velcro straps are used to hold small sensors in place)

Our technicians will attach the sensors to you before 10pm and you can then go to sleep whenever you wish. While you are asleep the sensors will send information to a computer about your breathing patterns and oxygen levels. The sensors are removed the following morning at about 6am.

If you have a chest problem we will record your oxygen level using a finger clip and your carbon dioxide level using a sensor pad strapped to your forearm.

All studies are completely painless and most people are able to enjoy a normal night’s sleep. A nurse will be on hand during your sleep study.

Where will I have my sleep study?

Your sleep study will take place in one of our sleep study rooms on Victoria ward, second floor, Fulham wing. The ward can be reached by lift.

On arrival you will be met by a nurse who will help you settle in and will go through some initial tests with you.

How long does a sleep study take?

An overnight stay is all that is needed. Before you come into hospital you will be given a time to arrive on the ward. Generally you will be asked to arrive during the afternoon so that the doctors can discuss your symptoms with you.

You will normally be free to leave at about 10am the next day.

What do I need to bring with me?

All you need for your overnight stay is:

  • nightwear

  • washing kit

  • towel

  • reading material (if desired)


Please do not bring jewellery, valuables or large sums of money with you. We cannot accept responsibility for any loss or damage to your personal property.


An evening meal is provided in your room at 6pm and breakfast is provided the following morning.

When will I know the results?

Before you leave to go home your doctor will discuss the results of your study with you and any possible treatments.

Admission information

It is very important that you confirm your admission with the sleep study administrator as soon as possible by telephoning 020 7351 8984 (direct line).

Please let our administrator know if you have any other special needs such as use of a wheelchair, or if you need diabetic, kosher, vegetarian or other specially prepared meals.  

Sleep apnoea is caused by upper airway collapse during sleep; patients literally stop breathing, although for such a short amount of time that they don’t usually wake up.

Royal Brompton centre for sleep

Find out more about the facilities available at Royal Brompton Hospital for your sleep study. 

Read more about the sleep centre at Royal Brompton Hospital

What's it like to come in for a sleep study

Read one patient's experience of coming in for a sleep study at Royal Brompton Hospital.

Read about this patient's experience