Sleep Study and Investigations at Parkside Hospital

What is a sleep study?

A sleep study is an investigation that monitors things like your breathing, oxygen levels, brain activity or movements while you sleep, to help find out what's causing a sleep problem. It can be done in your own bed at home, or overnight in hospital, depending on what your doctor needs to check.

What conditions does it investigate?

A sleep study can help investigate a wide range of sleep problems, including:

• obstructive sleep apnoea (OSA), where your breathing repeatedly stops and starts during sleep
• insomnia, difficulty falling or staying asleep
• narcolepsy, a condition that causes sudden, overwhelming sleepiness
• restless legs syndrome
• parasomnias, such as sleepwalking or other unusual behaviour during sleep
• excessive daytime sleepiness or irregular sleep patterns.

What are the benefits of having a sleep study?

Sleep disorders can affect far more than how tired you feel. Left undiagnosed, they're linked to a higher risk of health problems such as diabetes, heart disease and obesity, and can affect your concentration and safety, including your ability to drive. A sleep study gives you and your specialist clear evidence of what's happening while you sleep, so any treatment can be properly targeted to your problem.

Many private sleep services can also offer a fast turnaround, with some centres offering appointments within days of referral and results back to your doctor within days of testing.

Are there different types of sleep study?

There are several different types of sleep study, and which one you have depends on what your doctor needs to find out:

• overnight oximetry, a simple sleep study that measures your oxygen levels using a small clip on your finger, usually done at home
• respiratory polygraphy, which adds bands around your chest and abdomen to measure movement, plus a sensor near your nose to track airflow, also usually done at home
• polysomnography (PSG), a more detailed study that also records your brain waves (EEG), heart rate and other body signals, usually requiring an overnight stay in hospital
• actigraphy, wearing a motion-tracking watch for around 2 weeks, sometimes longer, to see your sleep-wake pattern over time, alongside a sleep diary you fill in yourself
• daytime tests such as the Multiple Sleep Latency Test (MSLT), which looks for signs of narcolepsy, or the Maintenance of Wakefulness Test (MWT), which checks how well you can stay awake, for example to assess fitness to drive. These are usually done the day after an overnight polysomnography.

What happens before your sleep study?

Before some studies, your doctor may ask you to complete a questionnaire, such as the Epworth Sleepiness Scale, to help understand your symptoms.

If you're having a home-based study, you'll usually collect the recording equipment from the hospital or sleep centre, sometimes after a phone call to check details such as your usual bedtime, waking time, and, for some tests, your waist size, so the equipment can be prepared for you.

If you're staying overnight in hospital for a more detailed study, you'll usually be asked to arrive in the afternoon so the team can discuss your symptoms with you before your study begins that evening.

What happens during the study?

For an overnight hospital-based study:

1. You arrive at the sleep centre, usually in the afternoon, and a team member helps you settle in.
2. Sensors are attached to your skin, or over your nightclothes, typically during the early evening. These might include a finger clip to measure oxygen levels, a sensor near your nose to track airflow, bands around your chest and abdomen, and, for a full polysomnogram, sensors on your head to record brain activity.
3. You can ask for a chaperone to be present while equipment is attached, if you'd prefer.
4. You sleep as normally as you can, while the equipment records your breathing, oxygen levels, movements and, if applicable, brain waves overnight.
5. The equipment is removed the following morning, usually between 6am and 7am.
6. You may be asked to complete a questionnaire about your night, and you're usually free to go home by around 10am, sometimes after breakfast and a shower.

For a home-based study, you fit the equipment yourself, following written or video instructions, wear it overnight in your own bed, then return it to the hospital or sleep centre the next day.

What happens after your sleep study?

There's no physical recovery needed. Sleep studies are painless and don't involve any procedure on your body beyond wearing monitoring equipment. Once your study is finished, the focus shifts to your results.

• Your recordings are downloaded and analysed, sometimes by a physiologist first, with a sleep specialist then reviewing and reporting on the findings
• A full report is usually sent back to your referring doctor within about 5 to 10 days of your test, but this may vary
• You'll usually be given a follow-up appointment to discuss your results and, if needed, next steps or treatment. If your results show no problems, some services will simply write to let you know
• If your study suggests obstructive sleep apnoea and you need treatment such as CPAP, a machine and mask that keeps your airway open while you sleep, this is usually arranged and explained at a follow-up appointment
• If you haven't heard about your results or a follow-up within a few weeks of your test, contact the department, as this shouldn't usually take longer than that.