There’s no sugarcoating it—sleeping in a lab feels strange. You’ve got electrodes attached to your scalp, face and legs…you’re in an unfamiliar bed…and a night-vision camera is recording your every move.
So why would you leave the comfort of your own bed to do such a thing? If your sleep is being disrupted but you’re not sure why, a sleep study can be the best way to finally get the answers you need.
Here’s what to expect during a sleep study—and how to ensure that you get the most accurate results…*
INSIDE A SLEEP LAB
People who have problems during sleep often end up in the office of a sleep specialist (usually an otolaryngologist, a pulmonologist, a cardiologist or a neurologist), who is board-certified in sleep medicine and trained to evaluate patients for sleep disorders. When it comes to diagnosing most sleep problems, the gold standard is a sleep study (also known as a polysomnogram).
During a sleep study, your brain waves, heart rate, breathing, blood oxygen levels and leg and eye movements are measured. This important data helps your doctor not only diagnose your condition but also determine the best treatment.
What a sleep study can identify…
• Sleep apnea. Your doctor may suspect obstructive sleep apnea (OSA)—which affects one-quarter of all American adults between the ages of 30 and 70—if you have morning headaches, awaken with a dry mouth and/or suffer from excessive daytime drowsiness. If your bed partner complains that you snore, that also can be a red flag.
With OSA, your upper airway closes during sleep, temporarily halting your breathing. This can happen for 10 seconds or longer dozens or even hundreds of times a night.
The sleep study calculates the number of times breathing either stops or becomes abnormally slow. For example, OSA would be assessed as mild if you stop breathing five to 14 times per hour…moderate (15 to 30 times per hour)…or severe (more than 30 times per hour).
• Periodic limb movement disorder (PLMD). This condition is suspected if you have uncontrollable leg movements when you are trying to sleep. It is closely related to restless legs syndrome (RLS), which causes an overwhelming urge to move your legs during periods of inactivity (during the day or night). PLMD causes similar symptoms—along with telltale muscle twitches that occur only at night.
Because RLS occurs when you’re awake, it usually can be diagnosed based on symptoms alone. A sleep study identifies PLMD and its severity, which helps determine the best treatment approaches.
Many people get relief from PLMD by massaging their legs, walking and stretching. If those approaches aren’t effective, pramipexole (Mirapex) is a prescription medication that is effective for both RLS and PLMD.
• Narcolepsy. You or your doctor may suspect this condition if you suffer from excessive daytime sleepiness, nap attacks and/or hallucinations as you fall asleep or awaken.
Testing takes a total of about 20 hours and typically consists of an overnight polysomnogram, immediately followed by a multiple sleep latency test, which consists of a series of five 20-minute naps scheduled at specific intervals throughout the following day. Your doctor will evaluate how quickly you fall asleep, what stages of sleep you enter and for how long. Narcolepsy is typically treated with medications, including stimulants such as modafinil (Provigil)…or antidepressants such as fluoxetine (Prozac)…and/or scheduled napping.
• Erectile dysfunction (ED). This condition is suspected if a man has difficulty achieving and maintaining an erection. A sleep study can help determine the cause. For example, during a penile plethysmograph, a pressure-sensitive rubber ring is placed at the base of the flaccid penis before the patient falls asleep. Most men experience at least some level of erection while sleeping, especially during rapid eye movement (REM) sleep. If the ring detects an erection overnight, the patient’s ED is deemed to be psychological in nature and not caused by obstructed blood flow. Treatment usually includes psychotherapy.
Important: You may assume that a sleep study would be the best way to diagnose insomnia, but the test is not used for this purpose—people who suffer from insomnia tend to sleep even less in a sleep study environment than in their own beds, making an accurate diagnosis more difficult. Instead, your sleep specialist will make the diagnosis after taking a thorough inventory of your physical and mental health, discussing your sleep routine and reviewing your sleep diaries.
HOW TO GET ACCURATE RESULTS
To get the most accurate results from your sleep study…
• Don’t use hair products. These products can prevent electrodes from properly sticking to your scalp and body.
• Bring your favorite pillow, as well as a pair of comfortable pajamas (preferably button-down so the technician can access your chest to place electrodes), a good book or anything else that gives you comfort.
• Ask about sleep medications. If you feel anxious and want to take a medication to make you feel sleepy, discuss this beforehand with your doctor and tell the lab technician who is administering the test if you have taken anything for sleep.
You can typically use an over-the-counter product, such as Tylenol PM. You should avoid a benzodiazepine such as alprazolam (Xanax)—this type of drug can worsen sleep apnea.
• Use caution with alcohol. Some labs advise against drinking alcohol before your test. However, if you normally have a drink in the evening, ask your doctor about continuing that practice so the study will accurately assess what is happening in your brain and body. Most labs won’t allow alcohol, so enjoy it at home and have someone drive you to and from your appointment.
RATHER STAY AT HOME?
Even though they are not as reliable as a sleep study in a lab, home sleep tests (HSTs) are becoming an increasingly popular option to identify OSA.
How it works: Your doctor sends you home with a small kit that contains the equipment you need. Before bed, you secure a belt and a small data recorder around your chest. The recorder attaches to an airflow sensor that’s worn under your nose to monitor your breathing during sleep. A pulse oximeter placed on your finger records oxygen saturation levels to identify times when you stop breathing during sleep. After one to three nights of recording, your doctor uploads and reviews the data.
About 10 companies manufacture HSTs, including ApneaLink Air and NovaSom. A home sleep test costs about $250 to $300 versus $1,300 and up for a sleep study conducted in a lab. Like standard sleep studies, an HST is usually covered by insurance as long as you have OSA symptoms.
What about apps? Some smartphone apps claim to wirelessly test for sleep apnea at home by detecting and analyzing snoring or by emitting sound waves from the phone’s speakers to track breathing patterns. Beware: These products are not sensitive enough to provide accurate results. You could get a false reassurance by using one of these apps, which would delay an accurate diagnosis.
*A sleep study should be performed at a center that is accredited by the American Academy of Sleep Medicine. To find such a center, go to SleepCenters.org.