Between 50 to 70 million people throughout the United States struggle with a sleep disorder. Sleep disorders can significantly affect your energy level, mood and overall quality of life. To treat a sleep disorder, you must first receive an accurate diagnosis. Polysomnography can provide your doctor with the necessary information to diagnose and treat the underlying cause of your sleep disorder.
The Purpose of Polysomnography
Polysomnography (also referred to as a sleep study) is a non-invasive exam that allows medical professionals to monitor you as you sleep to see what occurs in your brain and body. A sleep study must be conducted overnight at a sleep lab. As you sleep, an EEG monitors you as you cycle through REM and non-REM stages throughout the night to identify potential disruptions.
Who Needs a Sleep Study?
Sleep studies are an essential diagnostic tool that physicians can use to identify and diagnose various sleep disorders. However, they aren't always necessary. Depending on your overall health and symptoms, your doctor may prescribe a sleep study.
If you are experiencing excessive daytime fatigue, drowsiness, difficulty concentrating or depression due to sleep issues, you may be a good candidate for a sleep study. People who are obese are at a higher risk for sleep apnea and should also be screened. Your primary doctor can help you determine whether you are a good candidate for a sleep study.
What Can a Sleep Study Measure?
Sleep studies provide a thorough picture of the overall quality of rest you receive and what may be occurring in your body that affects your sleep. Various electrodes are placed on your body before you begin. These electrodes monitor:
- Blood oxygen levels
- Leg movements
- Breathing patterns
- Muscle tone
- Heart rhythm
- Sleep stages through brainwave activity
The data from your sleep study is recorded by a technologist and then evaluated by your doctor. Once your physician reviews your results, they can determine a diagnosis and provide you with an appropriate treatment plan.
What Can a Sleep Study Diagnose?
Sleep studies are a vital diagnostic tool your doctor can use to diagnose a variety of sleep disorders, including:
- Sleep talking
- REM sleep behavior disorder
- Sleepwalking
- Narcolepsy
- Periodic limb movement disorder
- Restless leg syndrome
- Sleep apnea
- Insomnia
The type of sleep study you undergo depends on your symptoms and which study will provide the best information for your doctor.
What Types of Sleep Studies Are Available?
There are several different types of sleep studies available. The kind you have will depend on your symptoms and suspected potential sleep disorders present.
Polysomnography
With polysomnography, a sleep technician monitors a person staying overnight at a specialized sleep clinic. Various functions are measured throughout the process, including brain and muscle activity, eye movements, respiratory effort, airflow, blood oxygen levels, snoring and heart rate. Your body positioning and movements are also monitored throughout the night.
Multiple Sleep Latency Test
If your doctor suspects your excessive daytime sleepiness is due to narcolepsy or another unknown cause, you may take a multiple sleep latency test. This test accurately measures how quickly you fall asleep and enter REM sleep while you nap during the day.
CPAP Titration
CPAP machines are a standard treatment for individuals diagnosed with sleep apnea. During a CPAP titration, a technologist will determine the appropriate amount of air pressure a person requires from their CPAP machine so they can use it properly at home. CPAP titration usually requires a follow-up sleep study. You may also undergo a split night study. During a split night study, polysomnography is used to diagnose sleep apnea, and then CPAP titration is applied during the second half of the night.
Home Sleep Apnea Testing
In some cases, individuals can conduct their sleep studies at home. You may receive an at-home sleep apnea testing kit if your doctor suspects you have sleep apnea. Home sleep apnea testing collects information about heart rate, respiration and other variables throughout the night. However, home testing provides much less information than polysomnography, and a technician does not monitor you throughout the night.
What To Expect During Your Sleep Study
Some people are apprehensive about sleep studies because they don't know what to expect. Sleep studies typically occur at a lab or a hospital. However, the rooms are designed to feel as comfortable as possible and usually feature regular bedroom furniture instead of clinical hospital beds.
After checking in, your technician will spend about an hour setting up the sleep study equipment. This equipment measures your vitals and records additional information to accurately paint a picture of your sleep quality. After your technician sets your equipment up, they will leave you alone to relax until you fall asleep.
The staff at a sleep clinic receive specialized training in sleep medicine. Many also specialize in related fields such as psychiatry, neurology and pulmonary medicine. Nurses, physician assistants, medical assistants and respiratory therapists may also be present.
Preparing for Your Sleep Study
It's best to go about your normal routine on the day of your sleep study. However, here are some general guidelines:
- Avoid caffeine and alcohol.
- Do not nap during the day.
- Stick to your normal routine.
- Wash styling products out of your hair since they may interfere with monitoring equipment.
Sometimes, your doctor may advise you to stop taking your regular medications. Some medications significantly impact your sleep patterns and may skew the results by influencing your sleep quality. You should not stop taking your regular medications unless your doctor instructs you to do so.
Your sleep study report should provide your physician with enough information to accurately diagnose the underlying causes of your sleep disruptions. In some cases, you may need to repeat a sleep study. If you frequently experience sleep issues, you may benefit from polysomnography. Talking with your doctor and explaining your symptoms will help them determine if a sleep study is right for you.