By studying sleep and its characteristics, scientists can better understand the process and discover how sleep affects our overall wellness. Sleep can be observed and measured in sleep labs. Using set parameters, researchers can use sleep tests to measure physiological functions as you sleep or try to sleep. This, in turn, can help diagnose and manage sleep disorders.
Sleep labs are usually located in hospitals or medical sleep centers, but you can sometimes participate in a sleep study at home. The data collected from these labs can identify your sleep stages of REM and NREM sleep during the night.
What Do Sleep Labs Measure?
Sleep studies use a variety of noninvasive technologies to gather data about your sleep. The data collected and studied usually includes:
- Airflow in and out of your lungs as you breathe
- Blood oxygen levels
- Body position and posture
- Brains waves (by echocardiogram)
- Breathing effort and rate
- Electrical activity of muscles
- Heart rate
- Eye movements
- Snoring, talking or any other noises you make during sleep
What Do Sleep Labs Test For?
Sleep studies can help identify sleep disorders and underlying conditions that contribute to sleep deprivation. If you’re experiencing sleep deprivation, daytime sleepiness, cognitive difficulties or emotional distress, a sleep study might help diagnose an underlying issue. Sleep labs often test for disorders such as:
- Sleep apnea
- Sleep-related seizure disorders
- Sleep-related movement disorders (REM behavior disorder)
- Restless leg syndrome
- Nocturnal epilepsy
Sleep labs can also be useful for patients who experience both nighttime breathing disorders and an associated health issue, such as congestive heart failure or diabetes.
Types of Sleep Labs
Not all sleep labs provide the same tests. Based on your individual symptoms, your doctor will determine the appropriate tests for you, which may include:
- Polysomnography (PSG): Also known as an all-night sleep study, this test measures how much and how well you sleep.
- Multiple Sleep Latency Test: This study is performed following a PSG. You’ll be instructed to nap for 20 minutes every two hours. This test evaluates how often and how quickly you fall asleep during the day and measures the presence and severity of daytime sleepiness.
- Daytime Maintenance of Wakefulness Test: You’ll be asked to sit in a bed and stay awake. The transportation industry uses this trial to evaluate sleepiness levels for driving or flying safety.
- CPAP Titration: Similar to an all-night PSG, this assessment uses a CPAP machine to determine how much air pressure is required to keep your airway open while you sleep.
- Split Study: This test combines a PSG and CPAP Titration into one night of analysis.
- Epilepsy Monitoring: This procedure is done in conjunction with a PSG or multiple sleep latency test. It monitors for evidence of seizures during sleep.
- Home Sleep Study: Some people opt for home testing, which can be more affordable and convenient. At-home testing is often used to observe and diagnose sleep apnea.
What to Expect During a Sleep Lab Procedure
Most sleep lab tests are performed at a sleep center. On the day of your assessment, you’ll be asked to arrive approximately two hours before bedtime. You’ll likely be provided with a comfortable, hotel-like bedroom. The doctor or technician will place electrodes and monitors on your body that will stay there as you sleep. Sometimes this equipment may irritate your skin, but any irritation should go away shortly after it’s removed.
During the night, the equipment will record your physiological functions. It measures how long it takes for you to fall asleep and enter REM sleep, any changes in your breathing or heart rate, if and when you stop breathing and any other movements. Your sleep will likely be recorded by a video camera.
How to Prepare for a Sleep Lab Test
On the day of your sleep study, you can follow your normal routine. If you’re a night shift worker, you can request to take a sleep test during the day, so it fits your sleep schedule. Your doctor will likely request that you avoid any sleep medicine, alcohol or caffeine, as these substances can interfere with your sleep. If you have any medications in your normal routine, your doctor will review them to factor in how they might affect your sleep. Antidepressants, benzodiazepines and opioids can all influence your sleep.
Sleep Study Results
Once your sleep test is complete, your doctor will review the results to determine a diagnosis and treatment plan. They’ll consider your breathing, brain waves and muscle movements in the context of your medical history and other symptoms. For those suspected of having sleep apnea, the doctor will review how often you stopped breathing compared to the Apnea-Hypopnea Index.
Are Sleep Labs Covered by Insurance?
Sleep labs can be expensive, but you may be able to cover the cost through your health care insurance. Most insurance policies require that your doctor provide a referral to a sleep lab and supply adequate medical evidence that indicates the necessity of diagnostic testing. Always check first because insurance policies may not cover diagnostic sleep labs for:
- Night terrors
- Restless leg syndrome
- Drug dependency
Sleep Labs During the COVID-19 Pandemic
Much of the equipment used for sleep tests can’t be properly disinfected, and nocturnal ventilator support may increase the risk of COVID infection as it can potentially spread droplets. As such, sleep labs are recommended to perform only necessary sleep tests for those who are acutely ill.
To continue operating, sleep labs are suggested to follow these recommendations:
- Check temperatures before and after sleep labs
- Communicate any patient respiratory symptoms or close case contact to team leaders
- Use facial masks and gloves
- Use full protective equipment when handling confirmed cases of infection
- Practice hand hygiene before and after the sleep lab and whenever else necessary
Have you been through a sleep study test at a sleep center or at home? If so, what worked (or didn’t work) for you? Comment below!