What is a sleep study?

The sleep study analysis and interpretation are part of an elaborate process that takes several hours of work by specially trained professionals who process or ‘score’ the large amount of data recorded during the study. The sleep specialists at Nithra have the right knowledge on sleep and its disorders to explain the collected information correctly. A typical sleep study contains over 800 pages of data (including brain waves, muscle movements, eye movements and the like) which are digitally recorded. As this is a time-consuming and labour-intensive process, the complete evaluation of sleep studies takes a while before the results are handed over to the patient– this duration will be communicated to you by the specialist.

Overnight Polysomnograph (Detailed Sleep Study)

Performed In The Sleep Center

An overnight visit to a sleep centre is likely to be a new experience for you. A sleep study or polysomnogram (somnus=sleep) is a diagnostic procedure to detect the intensity of sleep and sleep related problems, by recording measurements that identify different sleep stages and classify various sleep problems. All sleep studies at Nithra are closely monitored by a trained sleep technician throughout the night.

During the test, various activities in your body including brain waves, muscle movements, eye movements, breathing (through your mouth and nose), snoring, heart rate, and leg movements are monitored by small discs called electrodes which are applied to your head and skin with an adhesive while flexible elastic belts are strapped around your chest and abdomen to measure your breathing. A clip on your index finger or earlobe monitors the level of oxygen in your blood and your heart rate. With your consent, your sleep may also be videotaped to review any abnormalities observed during the study. The sleep technician will let you know if this is done.

None of these devices are painful and are all designed to be as comfortable as possible. If you have questions or concerns about the applications, our technicians are happy to address them once you arrive at the clinic.

Portable Four Channel Cardio respiratory Sleep Study

The overnight sleep study (Polysomnogram) which provides several details about your sleep is the ideal way to analyse several aspects of your sleep. However, due to logistic reasons your sleep specialist may discuss with you the other option, which is a portable sleep study which could be done at a location outside the sleep center. This may be your home, a friend’s place or a hotel room; details of which you could discuss with your doctor. Please note that this portable sleep study may be acceptable alternative in some situations, but may not provide all required information when a detailed analysis is required. It is important for you to discuss this with your sleep specialist. If a portable sleep study is decided upon, a technician comes to your place briefly at night (approximately 30 min) and hooks up a portable machine (almost of the size of a cell phone) – you will be able to freely move around and perform any routine activity with this equipment. The technician from Nithra clearly explains how to unhook the machine on the following day and will return to pick it up. The collected data is then analysed and you will need to schedule an appointment to discuss the results.


This is a portable study where the patient wears ‘a watch’ for five – seven days to help us monitor their sleep patterns.

FAQs on sleep studies

What are the specific instructions I should follow on the day of the sleep study?

At Nithra, we encourage ONE of your family members or friends to accompany you for the study and you could follow a few simple instructions.

  • Remember to wear loose fitting, comfortable clothing that buttons up in front.
  • Avoid caffeine (coffee, tea, colas, chocolate etc.) if possible after 2:00 p.m.
  • Avoid alcohol if possible.
  • Try not to nap in the day.
  • Before coming to the sleep centre, wash and dry your hair. Do not apply hair sprays, oils or gels.
  • Pack a light bag as you would for an overnight stay at a hotel or a friend’s house including comfortable nightwear, towel, toiletries etc.
  • If you prefer it, you could bring your own pillow.
  • Please take all your usual prescribed medications unless specifically advised otherwise. DO NOT discontinue any medication without first talking to the sleep specialist.

How will I be able to sleep in a strange environment with all those wires on me?

Though it is the prime concern, most people sleep quite comfortably without any significant problems! At Nithra we ensure that the surroundings (and especially the bedroom) are homely and comfortable, like a hotel room when you go on vacation. So please keep thoughts of a cold, bright, technical and impersonal-looking clinic out of your mind.

The technical equipment and technicians will be in a room separate from your sleeping room, and the electrode wires will be gathered together in a kind of ponytail behind your head so that you can roll over and change sleeping positions almost as easily as you would at home. The electrodes may feel strange on your skin at first, but most people do not find them uncomfortable or an obstacle to falling asleep. The sleep specialist understands that your sleep in the centre will not be exactly like your sleep at home and this does not interfere with obtaining the necessary information from your study.

What will happen after I complete the overnight sleep study?

You will need to schedule a follow-up visit with the doctor to discuss the results and recommendations for treatment. Sleep study results are not generally discussed over the telephone because of their complex nature. To fully understand the results of your sleep study, their implications and any treatment recommendations that are made, it is best to meet face-to-face with your healthcare professional. Additional procedures are occasionally needed to establish a complete diagnosis or plan a treatment – your sleep specialist will discuss this with you.