Sleep problems can mean big trouble. Not only can a lack of good sleep leave you feeling exhausted, it can impact your tasks of daily living. The only sure way for your health care provider to find out what is causing sleep problems is through a sleep study.

If you have symptoms of obstructive sleep apnea (OSA), especially excessive sleepiness (ES) or loud snoring, your doctor will probably refer you to a qualified sleep laboratory or clinic where you will stay overnight for evaluation. Sleep studies allow your provider to watch what your body does while you sleep—your brain activity, breathing patterns, eye movements, muscle activity, sleep positions and blood oxygen levels. Activity during the two stages of sleep, NREM and REM (Non-rapid Eye Movement and Rapid Eye Movement), will also be evaluated.

Sleep studies not only help confirm or rule out sleep apnea and other sleep-related disorders, they can also establish the severity and possible approaches for treatment. For example, the most common and effective treatment for OSA is continuous positive airway pressure (CPAP). With this treatment, you wear a special mask that fits over your nose and/or mouth while you sleep. A machine gently blows air through your nasal passages to help keep your airway open during sleep. The optimal CPAP level for each patient is determined during the sleep study.

What to Expect

Before the study, you will meet with the physician or sleep specialist at the sleep clinic to go over your medical and sleep history. Come prepared with questions so that you'll know what to expect the night of the study. During this first visit, you may be asked to complete forms about your sleep habits, medical history and overall functioning during the day. Don't be surprised if the health care professional wants to speak with your significant other because he or she may know more about your breathing patterns at night than you do.

When it's time for the study, a technician will connect electrodes to certain parts of your body that will monitor your body's functions during sleep. A microphone will be used to record your snoring and you will be observed on a television monitor throughout the night.

The sleep study may also include a combination of other tests including:

• Electroencephalogram (EEG) to measure brain waves
• Electroculogram (EOG) to measure eye movement
• Surface electromyogram (EMG) to measure chin and leg movements
• Electrocardiogram (EKG) to measure heart rate and rhythm
• Chest bands to measure breathing movements
• Other tests to gauge oxygen and carbon dioxide levels in the blood

Typically, none of these assessments are painful or invasive.

Your provider will schedule a follow-up appointment to review the results of the study.

Finding a Sleep Laboratory

Your health care provider will probably recommend a specific sleep center. A list of accredited sleep laboratories is available through the American Academy of Sleep Medicine by visiting www.sleepcenters.org. The site includes a map, so you can easily search your state. Sleep laboratories can be hospital-based or free-standing. You can also check with local hospitals, home health care companies and other health care professionals to find a testing facility.