What is a sleep study and do they work?

Published March 2025 | 5 min read
Expert contributors Dr Garun Hamilton, President of the Australasian Sleep Association;
Dr Marcus McMahon, GP specialising in sleep
Words by Tegan Forder

As we learn more about the importance of sleep, more and more Aussies are having sleep studies. But what are they and are they worth it?

Sleep is vital to our health and wellbeing, yet 66% of Australian adults experience at least one sleep problem and almost half have at least two sleep-related issues.

President of the Australasian Sleep Association Professor Garun Hamilton says you should think of sleep as one of the three pillars of good health. “We’ve known for a long time about good nutrition and physical activity being important, but sleep is the third critical pillar,” he says. “If we don't have good sleep, it impacts all other aspects of health.”

According to the Australian Institute of Health and Welfare, getting too much or too little sleep is associated with an increased risk of type 2 diabetes, heart disease, stroke, obesity and mental health conditions. It also impacts our quality of life, mood and digestion. 

How can sleep problems impact your mental health?

As well as the impact on our physical health, sleep problems are strongly linked to mood disorders like depression and can worsen symptoms of existing mental health conditions.

Prof Hamilton says the relationship between sleep and our mental and physical health cuts both ways.

“If you’ve got depression or anxiety or other mental health problems, we know they impact sleep and cause sleep problems.

“But it also goes the other way. If you’ve got sleep disorders like insomnia, we know this increases the risk of developing anxiety and depression. We can say the same with obstructive sleep apnoea.”

To combat this, Prof Hamilton says a growing number of people are taking part in sleep studies to properly diagnose disorders like sleep apnoea and insomnia.

What is a sleep study?

A sleep study is a test that measures and records:

• brain activity
• heart rate
• eye movement
• muscle activity
• respiratory effort
• blood oxygen levels.

Sleep studies can tell us detailed information about a person’s sleep patterns, breathing and sleep health, says Dr Marcus McMahon, who specialises in a range of sleep disorders.

“By observing a patient's sleep cycle and physiological responses, sleep studies help pinpoint specific issues, leading to a more accurate diagnosis and tailored treatment plan,” he says.

The studies help identify disorders that can’t be confirmed through a routine clinical examination alone, he adds. These disorders include:

• obstructive sleep apnoea
• central sleep apnoea
• insomnia
• periodic limb movement disorder
• narcolepsy
• restless legs syndrome
• parasomnias (like sleepwalking).

How to know if you need a sleep study

Sleep difficulties tend to be considered a problem when they occur a few times a week or more. Dr McMahon says common signs and symptoms to look out for include:

• excessive daytime sleepiness
• snoring or choking during sleep
• difficulty falling or staying asleep
• morning headaches
• frequent movements or sensations in the legs that disrupt your own or a partner’s sleep
• memory problems
• unexplained irritability or mood changes
• difficulty controlling hypertension (high blood pressure).

You’ll need a referral by a sleep or respiratory specialist to undertake a sleep study. A GP can also provide a referral if a screening questionnaire shows you may be at high risk of sleep apnoea.

Medicare covers sleep studies done in a public hospital but you can also do your sleep study in a private hospital or sleep laboratory. Using our cost indocator tool, you can understand the typical out-of-pocket costs HCF members can expect to pay for a sleep study in a hospital or sleep laboratory, and learn how your choice of doctor affects that cost. 

Children can take sleep studies under the guidance of a paediatric sleep specialist, particularly if they’re showing signs of sleep apnoea, excessive daytime sleepiness or other sleep-related issues. In Australia, only sleep testing conducted in a laboratory is available for children, with no Medicare rebate offered for at-home sleep tests.

What to expect during a sleep study

During a sleep study, different electrodes, wires and probes are attached to your body to measure your brain and other activity. Health professionals may:

• measure your brainwave activity to determine different stages of sleep
• track eye movements to help identify rapid eye movement (REM) sleep
• monitor your muscle activity
• record your heart rhythm and blood oxygen saturation
• monitor your chest and abdominal movement
• measure the airflow through your nose and mouth.

You can watch this video to help prepare for a sleep study.

Types of sleep studies

You can do your sleep studies in a sleep centre laboratory, hospital or at home. While a laboratory or hospital test is more comprehensive, Prof Hamilton explains it depends on the patient, their needs and their diagnosis. For patients who have many chronic diseases or are in poor general health, a laboratory test is often a better option.

“Patient preference factors can come into it as well,” says Prof Hamilton. “Some patients will have a lot of anxiety, for example, about sleeping in a laboratory, and that may impact how well the test can be performed. So, for those people, a home test is a good option.”

Overnight laboratory sleep study

Laboratory or hospital sleep studies can make a diagnosis or test how well treatments are working. Overnight staff help you and make sure the results are being recorded correctly.

There are two types of in-lab sleep studies:

• Standard sleep study: Records brain activity, eye movement, muscle activity, heart rate, breathing patterns, blood oxygen levels and leg movements.
• Split-night sleep study: Designed to improve sleep quality for people already diagnosed with a disorder. The first half is for diagnostic testing, and the second half uses a therapeutic device – usually a continuous positive airway pressure (CPAP) or mandibular advancement splint (MAS) device.

At-home test for sleep apnoea

A home sleep apnoea test is a simplified sleep study that uses sensors to record airflow, breathing effort and oxygen levels with the results analysed later. This test is mainly done to investigate obstructive sleep apnoea if you have typical symptoms, like loud snoring or daytime sleepiness. At-home tests can be bought at your local chemist and can be done in one night. The test involves using a device to record your sleep patterns. You usually get your results in seven to 10 days through the company who made the sleep test device. However, these tests generally aren’t as accurate as a GP-led test in a laboratory.  

Vigilance testing

Prof Hamilton says vigilance testing is used to assess people who are excessively sleepy. There are two types: multiple sleep latency and maintenance of wakefulness.

The multiple sleep latency test, which can help diagnose conditions like narcolepsy, involves an overnight study followed by a daytime stay in the laboratory. During the daytime visit, you try to nap and are tested on how quickly you fall asleep.

The maintenance of wakefulness test is similar, but instead of napping during the day, you sit quietly in a dark room and try to stay awake. This looks for how well you can stay awake.

Learn more about how to prepare for a sleep study.

What happens after a sleep study

Dr McMahon says it’s important people go back to their GP or sleep specialist after a study.

“A GP or sleep specialist will review the results and recommend appropriate treatments or lifestyle modifications. This may include CPAP therapy, a mandibular advancement splint (which is like a mouth guard), sleep position modification devices, cognitive behavioural therapy for insomnia or medications for specific disorders,” he explains.

Sleep studies can be a powerful tool for diagnosing conditions impacting sleep, adds Dr McMahon, and with the right treatment and lifestyle changes, many sleep disorders can be managed.

“Don't hesitate to consult a health professional if you're concerned about your sleep – getting help is the first step towards better rest and improved health,” he says.

Remember, the first step is to book a GP appointment to discuss any sleep problems and get a referral to a specialist. Our partnership with GP2U, an online video GP service, makes it easier to access telehealth services. Eligible members^* can access a standard GP consultation (up to 10 minutes) for a fee of $50. Eligible members who live in regional Australia can access one standard 15-minute online consult with GP2U at no cost^{^}.

You can also get further advice through our Second Opinion⁺ service.

Learn how to build better sleep habits

If you want to lay the foundations for healthy sleep habits, the Sleepfit app can assess your sleep quality and help you identify sleep issues, recommend improvements and give you access to personalised tools.

Thanks to our partnership with Sleepfit Solutions, eligible HCF members with hospital or extras cover can get a free 12-month subscription to the Sleepfit app^#, designed to improve sleep and overall wellbeing. Help for a better night's sleep – that’s Uncommon Care.