Sleep Tests: Understanding Their Importance And Benefits

Sleep tests, or polysomnography, are done to monitor and record various body functions during sleep. Sleep studies are used to help diagnose sleep disorders such as sleep apnea, restless legs syndrome, narcolepsy, insomnia, and REM sleep behaviour disorder. They are also used to evaluate certain causes of excessive sleepiness. The tests are performed in specialised centres or at home, depending on the situation.

To diagnose sleep disorders

Sleep tests are done to diagnose sleep disorders. The most common type of sleep test is a polysomnogram, which involves recording multiple systems in the body while the patient sleeps. Sensors are placed on the patient's head and body to monitor brain activity, eye movement, heart rate, and breathing patterns. This data helps doctors diagnose sleep disorders such as sleep apnea, periodic limb movement disorder, narcolepsy, restless legs syndrome, insomnia, and nighttime behaviours like sleepwalking and REM sleep behaviour disorder.

Polysomnography is a non-invasive, overnight exam that takes place in a sleep lab, usually set up in a hospital or sleep centre. An EEG (electroencephalogram) is used to monitor sleep stages and the cycles of REM and non-REM sleep. The test also measures eye movements, blood oxygen levels, heart and breathing rates, snoring, and body movements.

The data from a polysomnogram is usually collected by a technologist and then evaluated by a doctor, which can take up to two weeks. The results help doctors determine the best treatment options for the patient.

In addition to polysomnography, there are other types of sleep studies, such as the Multiple Sleep Latency Test, which measures how quickly someone falls asleep and enters REM sleep during daytime naps, and CPAP Titration, which determines the amount of air pressure needed from a CPAP machine for the treatment of sleep apnea.

Sleep studies are an important diagnostic tool for sleep disorders, providing conclusive evidence that cannot always be obtained during a regular office visit. They help doctors diagnose and treat a variety of sleep disorders, improving the patient's sleep quality and overall health.

To rule out other health issues

Sleep tests are often used to rule out other health issues. They are a diagnostic tool that can help healthcare providers to identify or rule out health issues. They are usually recommended when a patient presents symptoms of conditions that affect sleep, to determine the best treatment course or evaluate the effectiveness of completed treatments.

Sleep studies are particularly useful in diagnosing conditions that affect or disrupt the brain, nervous system, breathing, and heart function. These include sleep apnea, periodic limb movement disorder (including restless legs syndrome), certain types of seizures and epilepsy, night terrors, nocturnal panic attacks, sleepwalking, and other sleep behaviour-related disorders.

The data collected from a sleep study provides a comprehensive view of an individual's sleep quality and can help healthcare providers identify any underlying health issues that may be disrupting their sleep. For example, if a patient is experiencing excessive daytime sleepiness, a sleep study can help determine if this is due to narcolepsy or another underlying condition.

Additionally, sleep studies can be useful in ruling out sleep disorders as a potential cause of certain symptoms. For instance, if a patient is experiencing fatigue, drowsiness, depression, or difficulty concentrating, a sleep study can help determine if a sleep disorder is contributing to these symptoms.

In some cases, a sleep study may be recommended to rule out sleep disorders before diagnosing a patient with a mental health condition, such as depression or anxiety. Sleep disorders can often mimic or exacerbate the symptoms of mental health conditions, so ruling out sleep issues can help ensure a more accurate diagnosis and effective treatment plan.

To evaluate excessive sleepiness

Sleep tests are often carried out to evaluate excessive sleepiness. Excessive sleepiness, or hypersomnia, is a condition characterised by a strong desire to sleep during the day or oversleeping. Other symptoms include low energy, slow thinking or speech, and anxiety.

One tool used to evaluate excessive sleepiness is the Epworth Sleepiness Scale (ESS), a self-assessment that helps healthcare providers understand how daytime sleepiness affects the patient. The ESS involves eight questions about common scenarios and activities that may make the patient sleepy, which are answered on a four-point scale. The results indicate whether the patient's sleepiness is normal or abnormal, and whether further testing is required.

Polysomnography, or a sleep study, is another tool used to evaluate excessive sleepiness. This test measures various body functions during sleep, including brain activity, eye movement, heart rate, and breathing patterns. The data collected helps doctors diagnose sleep disorders such as sleep apnea, restless leg syndrome, and narcolepsy, which may be causing the patient's excessive sleepiness.

The Multiple Sleep Latency Test (MSLT) is also used to evaluate excessive sleepiness, specifically to diagnose daytime sleepiness that may be due to narcolepsy or idiopathic hypersomnia. This test measures how long it takes a person to fall asleep and how quickly they enter REM sleep during daytime naps.

To determine treatment

Sleep tests are performed to determine the best treatment for a patient's sleep disorder. The data collected from a sleep study can be used to diagnose a patient's condition and subsequently determine the best treatment.

Sleep studies are often recommended when a patient presents symptoms of conditions that affect sleep, such as sleep apnea, restless leg syndrome, narcolepsy, insomnia, and sleepwalking. The data collected from a sleep study can help healthcare providers determine how to treat these conditions.

For example, if a patient is suspected to have sleep apnea, they may be asked to undergo a Continuous Positive Airway Pressure (CPAP) titration test. During this test, a technologist determines the amount of air pressure the patient needs from the CPAP machine so that it can be properly programmed for home use.

Additionally, sleep studies can also be used to assess the effectiveness of alternative treatments for sleep disorders. For instance, if a patient has undergone surgery or used an oral appliance to treat sleep apnea, a follow-up sleep study can be conducted to check the success of the treatment.

The data collected from a sleep study typically takes up to two weeks to be evaluated by a doctor, who will then discuss the results and treatment options with the patient.

To check treatment effectiveness

Sleep tests are often performed to check the effectiveness of a treatment. Healthcare providers usually recommend this test when a patient has symptoms of conditions that affect sleep, to determine how to treat those conditions or to see if completed treatments worked.

Sleep tests can be used to check the effectiveness of treatments for conditions that affect or disrupt the brain, nervous system, breathing and heart function. These include sleep apnea, periodic limb movement disorder (including restless legs syndrome), certain types of seizures and epilepsy, night terrors, nocturnal panic attacks, sleepwalking, and other sleep behaviour-related disorders.

For example, if a patient has undergone surgery, weight loss, or other treatments for sleep apnea, a follow-up sleep study can be a useful way to check if the treatment was successful. Similarly, if a patient has tried alternative treatments for sleep apnea, such as an oral appliance from a dentist or a surgical treatment, a second sleep study can be used to check the effectiveness of these treatments.

Sleep studies are also useful for checking the effectiveness of treatments for excessive daytime sleepiness. If a patient is still too sleepy, a sleep study may be used to dig deeper and reassess other conditions that may be triggering the fatigue. Multiple sleep latency testing (MSLT) may be performed as a follow-up to check for narcolepsy, hypersomnia, or normal levels of daytime sleepiness.

Sleep studies are a common way to check the effectiveness of treatments for sleep-related issues, with hundreds of thousands of sleep studies taking place annually.

Frequently asked questions