If you’re concerned you have a sleep disorder, such as sleep apnea or insomnia, you may have found yourself visiting your doctor. After some questions about your sleeping habits, your doctor may have decided it’s time for you to get an official diagnosis.
Today there are thousands of sleep clinics in the United States, and the number keeps growing. Learn more about how to choose a sleep clinic and what to expect during your sleep study.
What is a sleep clinic?
In essence, a sleep clinic is a medical lab where patients are monitored either overnight or during the day to observe how they sleep. Each room is outfitted with appropriate medical monitoring equipment that’s manned by medical staff trained in sleep medicine. Based on the data provided by your sleep study, the supervising physician will diagnose whether or not you have a sleep disorder.
Sleep clinics are primarily diagnostic centers. They may be part of a hospital, but most clinics are standalone. These clinics usually have a supervising physician but the majority of the work is done by technicians. The technicians will be the one conducting your test and monitoring you. Then they’ll share the data with the doctor who will interpret the results and provide a diagnosis.
What are the patient rooms like?
Beside the bed, the patient rooms in a sleep clinic contain medical equipment to monitor you while you sleep. You’ll be hooked up to this equipment via wires and sensors. Different pieces of the equipment monitor various vital signs while you sleep, such as your brain waves, breathing patterns, and eye and body movement.
There is also a observation window on one side, with an intercom. The sleep clinic technician will stay in this other area for the duration of your study, able to watch you while you sleep and communicate with you over the intercom.
In hospital sleep clinics, the patient rooms often look similar to other hospital rooms, but with more comfortable beds and sleep diagnostic machinery. The rooms in a standalone sleep clinic, on the other hand, tend to look more like hotel rooms. Many sleep clinics aim to make the rooms a hospitable environment, since they’re aware of how difficult it can be for someone to fall asleep in a strange environment.
Why have a sleep study done?
If you’ve been having trouble with chronic snoring, excessive daytime sleepiness, or general difficult falling or staying asleep, it’s possible you have a sleep disorder. Typically doctors refer people to sleep clinics when behavioral changes and other methods have proved ineffective for solving an apparently sleep-related problem.
For example, if you visited your primary care physician about snoring, they may have suggested the following advice: switch from sleeping on your back to your side, change your diet and exercise, and try to lose weight. You may also have been advised to follow a set sleep schedule, to ensure you get a full 7 hours in. If, after making these changes, your snoring hasn’t improved, the doctor may order a sleep study to determine whether your snoring is actually sleep apnea.
By reviewing all of the data from your sleep study, a doctor can provide an informed diagnosis. With many sleep disorders, the symptoms display while we are asleep. As a result, we may wake up feeling unrested without knowing why. Even if we were awake during the symptoms, we still likely wouldn’t notice them, as they are tied to physiological responses we’re unable to track ourselves, such as blood pressure, heart rate, and brainwave activity.
Your brain wave activity in particular is a huge diagnostic tool, since we display different brain wave activity according to the stage of sleep we’re in. By monitoring your sleep during the night, a sleep study can reveal if you’re not spending sufficient time in various stages of sleep, such as restorative deep and REM sleep.
Remember: sleep clinics do not cure your disorder. They diagnose a problem or confirm a preliminary diagnosis.
What can a sleep study diagnose?
Sleep clinics diagnose a variety of sleep disorders. Here are some of the most common:
Sleep apnea is a sleep-related breathing disorder where the individual momentarily stops breathing while asleep. Whether the person realizes it or not, the brain wakes them up just enough to initiate breathing again. Even if the person is not consciously roused, this constant interruption to sleep interferes with the restfulness of their sleep, resulting in excessive daytime sleepiness. It’s also dangerous because any stoppage of breathing is a health concern.
There are two main forms of sleep apnea:
Obstructive sleep apnea (OSA), which is caused by a physical blockage of the airways. This is the more common type and is associated with obesity.
Central sleep apnea (CSA), which is caused by a communication error between your brain and your breathing muscles.
A sleep study can diagnose which form of sleep apnea the patient has, which is important, since both require different treatments. Apnea is diagnosed based on the severity, or frequency, of these apnea episodes – referred to as the Apnea/Hypopnea index.
Insomnia is one of the most common sleep disorders, with mild insomnia affecting one in three Americans. It describes a general difficulty falling asleep or staying asleep, such as waking frequently during the night or waking up too early. Chronic insomnia is diagnosed when these conditions persist for months at a time. Insomnia is a major contributor to long-term sleep deprivation.
Insomnia testing may take a few days at a sleep clinic, during which you’ll be able to leave during the day and live your life as usual, going to work and running errands. Insomnia is one condition that can be heavily affected by environmental factors and mental health conditions like anxiety and depression. However, it can also be a symptom of another sleep disorder, in which case a sleep study can discover the root cause.
Narcolepsy describes a condition where even if the individual is getting sufficient sleep at night, they experience excessive daytime sleepiness during the day. Individuals with narcolepsy also fall asleep spontaneously during the day, severely disrupting their daily life and putting them at risk of injury.
To diagnose narcolepsy, sleep clinics perform both an overnight exam and a daytime exam. The daytime exam observes how spontaneously they fall asleep, and with what frequency, while the overnight exam is designed to see if another sleep disorder could be causing the daytime symptoms.
Restless leg syndrome (RLS)
RLS is a sleep-related movement disorder where the patient experiences an uncomfortably numb or tingling sensation in their lower limbs whenever they are lying down, like one does when going to bed. They can only find relief by moving the legs. This uncontrollable urge to constantly move their legs to relieve the pain sensation makes it challenging to fall asleep.
While RLS is commonly diagnosed from self-reported symptoms, a sleep study can help determine whether it is caused by another underlying sleep disorder.
Periodic limb movement disorder (PLMD)
PLMD is another sleep-related movement disorder where the individual makes repetitive, involuntary movements of the lower limbs frequently, but with PLMD these movements occur during non-REM sleep.
Sleep studies are often ordered since PLMD has a high association with other sleep disorders.
Sleepwalking is a parasomnia where the individual gets up, stands, and/or walks during deep sleep in the first half of the night. Since the individual is asleep when this is happening, they can easily injure themselves.
While most children usually grow out of sleepwalking naturally, a sleep study may be ordered to confirm the symptoms are not caused by sleep seizures or another disorder.
Rhythmic movement disorder
Rhythmic movement disorder is a disorder more common among children where the individual rocks their body in a repetitive pattern while falling asleep or just before entering light sleep. If the movements are violent it can put the person at risk of getting hurt.
LIke sleepwalking, the symptoms of rhythmic movement disorder can be confused with epilepsy. Sleep studies help discern the true cause.
REM behavior disorder (RBD)
REM behavior disorder is a sleep disorder tied to the REM stage of sleep. The individual makes loud vocalizations during sleep and violently acts out their dreams through yelling, running, jumping, or other movements. Unlike night terrors, where the individual does not remember the episode upon waking up, individuals with RBD are typically alert upon waking and remember the episode for long after.
RBD is more prevalent among older adults. It is commonly confused with other sleep movement disorders. A sleep study, along with a neurological exam, can disentangle the symptoms of RBD from those of other health conditions.
Sleep bruxism is a sleep-related movement disorder where the individual grinds their teeth and tenses the related facial muscles during sleep, leading to severe dental health issues and disrupting the quality of their sleep. People often discover they have sleep bruxism because they wake up with headaches and begin to notice damage to their teeth.
Often, a special oral appliance is prescribed to prevent the individual from grinding their teeth at night. A sleep study is required to get the prescription.
What is tested during a sleep study?
Most sleep clinic studies require overnight visits, or even more than one night in the case of insomnia. However, some disorders, such as narcolepsy, may require an additional daytime exam for diagnosis.
Shift workers are the one exception to the overnight studies. Since they normally sleep during the day, the exam may alternately be scheduled during the daytime to accommodate their typical sleep schedule.
Four main types of tests are performed in sleep clinics:
1. Polysomnogram (PSG)
Polysomnograms are the most common test performed. Thanks to electrodes and sensors attached to your body, this overnight exam measures and records your vital functions while you sleep, including your brain activity, heart rate, blood pressure, oxygen levels, body and eye movements. A polysomnogram is a critical testing tool for most sleep disorders, including sleep apnea, sleep-related movement or seizure disorders, and insomnia.
In cases of narcolepsy and sleep apnea, a MSLT may be ordered after a polysomnogram has been completed. These exams take place during the daytime. During the MSLT, the patient will have five 20-minute nap times that are each scheduled 2 hours apart. The technician monitors brain activity and eye movements, in order to measure how sleepy the patient gets, how quickly and with what frequency they enter REM sleep, and whether their sleep apnea treatments are working properly.
Like a MSLT, this exam is also sometimes ordered after a polysomnogram has been completed. The MWT is designed to monitor the person’s alertness and ability to stay awake during the day. It measures the extent of their excessive daytime sleepiness. MWTs help assess the suitability of someone for long work hours (like truck driving), and also whether sleep apnea treatments are proving effective.
This patient is preparing for a MWT:
4. CPAP Titration
If the doctor finds sleep apnea during polysomnogram, another overnight sleep study is performed, where they determine the right air pressure for your CPAP machine. CPAP therapy is the most effective treatment for sleep apnea, but the air pressure must be calibrated correctly for the patient to find it comfortable enough to sleep with.
This patient’s breathing is being monitored for his CPAP titration study:
What happens during a sleep study?
Sleep studies are completely non-invasive exams that take place overnight at a sleep clinic. In order to allow for 7 hours of testing, sleep clinics normally arrange for you to arrive between 8 and 10 at night so you can leave between 6 or 8 am (providing 2 hours of wiggle room).
When you arrive at the sleep clinic, a sleep technician will check you in. They’ll assemble your paperwork and have you complete any remaining forms. Next, they’ll test your vital signs like you’re used to during a normal doctor’s appointment, such as your blood pressure. Then, they’ll begin explaining the exam to you as they start attaching the equipment to your body.
Electrodes are attached to your scalp with a paste to measure your brainwave activity via electroencephalography and indicate with stage of sleep you’re in
Electrodes are attached to your face with tape, near your eyes and chin, to measure your eye movements (indicating the stage of sleep) and potential teeth grinding
Electrodes are placed on each leg to measure any limb or muscle movements
Two electric belts are placed around you, one around your chest and one around your stomach, to monitor your breathing
A clear plastic nasal tube observes your breathing activity via a nasal airflow sensor
An oxygen monitor is taped to one of your index fingers to detect your oxygen levels
Electrocardiography (EKG) monitors measure your heart rate and rhythm
A small microphone is attached to your throat to listen for signs of snoring
The wires attached to all of these sensors are long enough to allow you to move as normal during sleep.
Before you go to sleep, the technician will speak to you over an intercom from the other room, working to calibrate the equipment. Once everything looks good, they’ll tell you to go ahead and fall asleep. While you sleep, they’ll continue monitoring all of the data coming in from the computers.
Sometimes the technicians will let you sleep until you wake up naturally, and sometimes they will wake you at a preselected time. Once you’re up, the technician will carefully remove all of the monitoring equipment, give you a bit more paperwork to fill out, and then you can leave. Some clinics have shower facilities so you can get ready for the day there.
You won’t get any answers in the morning when you leave the sleep clinic. The technician will share your data with a doctor, who will then read and analyze the data, along with the rest of your medical history and any notes from your referring physician about your sleep.
About 7 to 10 days later, you should hear from the doctor with your results. Beyond providing you with your diagnosis, the doctor will review your potential treatment options if you do indeed have a sleep disorder.
How much does it cost to have a sleep study done?
A study at a sleep clinic can be expensive, starting at $1,000 or more, but many insurance programs will pay for it if your main doctor refers you to the clinic. The doctor who has been handling your sleep disorders should make the referral.
However, you can also self-refer yourself to a sleep study. If you self-refer, be aware that you’ll likely need to have a consultation first with the clinic’s sleep specialist doctor. Since a primary care physician won’t be forwarding over your medical history, the sleep clinic doctor will ask you the relevant questions needed to gather your medical history and determine whether a sleep study is the right choice for you.
How to choose a sleep clinic
There are many sleep clinics around the country; all large cities have a few. To choose a reputable sleep clinic that’s a good fit for you, look for the following:
1. Proper medical certification
The most important thing to look for when choosing a sleep clinic is that the sleep technologists monitoring your polysomnogram and the doctor providing your diagnosis all have the appropriate sleep certifications.
The members of your care team at a sleep clinic will include a sleep doctor, a sleep technician, and perhaps a sleep respiratory therapist. Confirm they have the following certifications:
Your sleep doctor, formally known as a sleep specialist, will be the one providing you with your diagnosis. They should have a MD or DO degree and be board-certified in sleep medicine. They may have additional accreditation through the American Academy of Sleep Medicine. A Board Certified Sleep Doctor indicates a doctor who underwent a separate two-year fellowship of specialized training in sleep medicine, in addition to their other medical training.
Sleep technologists, also known as polysomnographic technologists, are the ones keeping you company during your sleep study, monitoring all of your vital signs while you sleep. They will have one or more of the following certifications: Certified Polysomnographic Technician (CPSGT), Registered Sleep Technologist (RST), Registered Polysomnographic Technologist (RPSGT), and Sleep Disorders Specialist (SDS).
If you are diagnosed with sleep apnea, a sleep respiratory therapist will teach you how to use your CPAP machine. They will have a Sleep Disorders Specialist (SDS) certification, as well as either a Certified Respiratory Therapist (CRT) or Registered Respiratory Therapist (RRT) certification. They may have additional accreditation through the National Board for Respiratory Care.
In order to receive this accreditation, the center must meet certain requirements regarding the qualifications of the managing sleep doctor, and education and certification of the technicians. All individuals must also meet continued education requirements. Additionally, each facility is visited by a current Board Certified Sleep Doctor from AASM who reviews their sleep test records and inspects the facility.
You can find an AASM-accredited facility here. At the time of writing, the AASM has accredited over 10,000 sleep clinics and individual doctors nationwide.
3. Positive reviews
Beyond the medical expertise of the staff, it’s important for you to know what the patient experience is like at a sleep clinic. Look up the online reviews for clinics near you and ask to see patient testimonials.
4. In-network insurance coverage
Sleep studies can be costly, so look for an in-network facility to save more.
If you’re getting a sleep study to diagnose sleep apnea, some insurance companies require that you take a home sleep study first, so check if your clinic offers these. Home sleep tests are much more affordable, ranging from $200 to $500, and are designed to diagnose the severity of OSA.
5. Helpful resources
People who have the toughest time managing their symptoms or curing their insomnia are the ones without resources, so look for a clinic that provides a lot of educational information in a variety of formats. Take a look at their website. Do they run a blog, publish e-books, or host webinars? See if they provide helpful pamphlets when you visit.
If you’re fortunate enough to live in a large city with plenty of sleep clinics, you might narrow your list to a few based on proximity to your home or work. Visit these clinics before your exam to see if you like the environment.
How to prepare for a sleep study
If you have a sleep study scheduled, it’s likely the clinic will provide you with preparation and care instructions to follow before your exam. Even so, review the tips below to prepare yourself for your sleep study:
The week before your sleep study
In the days leading up to your appointment, live your life as normal, going to work or spending time on leisure activities. You do not need to do anything special to get the exam to work – this technology is designed to be able to diagnose your sleep disorders.
The day of your sleep study
Avoid drinking alcohol the day of the study.
Limit your caffeine intake before lunch.
Avoid napping. You want to have no problem falling asleep when you arrive.
Wash and dry your hair. Attaching electrodes to your scalp is easier when you have a scalp free of gels and oils.
Remove any nail polish from your index fingers, since an oxygen monitor will be attached to one of them.
The night of your sleep study
Arrive at the sleep clinic on time. Appointments are usually scheduled between 8 and 10pm.
Ensure that you have eaten dinner already and are ready to go to sleep.
Bring your sleep clothes, toiletries, and a change of clothes with you.
Bring any medications you are taking, and re-inform the technician of these medications.
Bring your sleep diary, if you’ve been keeping one, and share it with the technician.
Bring a boring book to occupy your mind and help you fall asleep.
During your sleep study
Don’t worry about it taking you longer than usual to fall asleep. Many people find sleeping in a new location difficult, although some find it easier to sleep at a clinic because they have nothing else to do there. Either way, the effect of a new location does not alter the results. The tests will still show the sleep disorders you have.