Tal Klatchko, D.O.


Pulmonary & Critical Care
Roper-St. Francis Hospital
Charleston, South Carolina
(843)763-3360

Sleep Study

Sleep apnea is a common disorder in which you have one or more pauses in breathing or shallow breaths while you sleep. In obstructive sleep apnea, the airway collapses or is blocked during sleep. If your doctor thinks that you have sleep apnea, he or she may schedule a sleep study. People usually aren’t aware of their breathing and movements while sleeping. They may never think to talk to their doctors about sleep- and health-related issues that may be linked to sleep problems.

What Are Sleep Studies?

  • Sleep studies allow doctors to measure how much and how well you sleep.
  • They also help show whether you have sleep problems and how severe they are.

Sleep studies can help doctors diagnose:

  • Sleep-related breathing disorders (such as sleep apnea)
  • Sleep-related seizure disorders
  • Narcolepsy
Sleep studies are important because untreated sleep disorders can increase your risk of :

  • High blood pressure
  • Heart attack
  • Stroke
  • Sleep disorders also have been linked to an increased risk of injury due to falls and car accidents.
  • Other medical conditions have been associated with sleep disordered breathing: heart failure, coronary heart disease (also called coronary artery disease), obesity, diabetes, transient ischemic attack (TIA, or “mini-stroke”).

Who Needs a Sleep Study?

  • If you often feel very sleepy, even though you’ve spent enough time in bed to be well rested
  • If you bed partner or you have noticed loud snoring, gasping, or choking sounds while you sleep or pauses in breathing during sleep.
  • It takes you more than 30 minutes to fall asleep at night.
  • You often wake up during the night and then have trouble falling back to sleep, or you wake up too early and aren’t able to go back to sleep.
  • You feel sleepy during the day and fall asleep within 5 minutes if you have a chance to nap, or you fall asleep at inappropriate times during the day.
  • You have creeping, tingling, or crawling feelings in your legs that are relieved by moving or massaging them, especially in the evening and when you try to fall asleep.
  • You have vivid, dreamlike experiences while falling asleep or dozing.
  • You have episodes of sudden muscle weakness when you’re angry, fearful, or when you laugh.
  • You feel as though you can’t move when you first wake up.
  • Your bed partner notes that your legs or arms jerk often during sleep.
  • You regularly feel the need to use stimulants, such as caffeine, to stay awake during the day.

How is a Sleep Study aka Polysomnogram (PSG) done?

  • A PSG usually is done while you stay overnight at a sleep center.
  • A PSG records brain activity, eye movements, heart rate, and blood pressure.
  • A PSG also records the amount of oxygen in your blood, how much air is moving through your nose while you breathe, snoring, and chest movements. The chest movements show whether you’re making an effort to breathe.
  • Your doctor also may use a PSG to find the right setting for you on a CPAP (continuous positive airway pressure) machine. CPAP is the most common treatment for sleep apnea.

What is a Split Night Study and/or CPAP titration?

  • A CPAP machine uses mild air pressure to keep your airway open while you sleep.
  • During the first half of the night, your sleep is checked without a CPAP machine. This will show whether you have sleep apnea and how severe it is.
  • If the PSG shows that you have sleep apnea, you may use a CPAP machine during the second half of the split-night study.
  • A technician will help you select a CPAP mask that fits and is comfortable.
  • While you sleep, the technician will check the amount of oxygen in your blood and whether your airway stays open. He or she will adjust the flow of air through the mask to find the setting that’s right for you. This process is called CPAP titration.
  • In some cases, this isn’t done all in the same night. Some people need to go back to the sleep center for the CPAP titration study.

Your doctor may recommend a followup PSG to:

  • Adjust your CPAP settings after weight loss or weight gain
  • Recheck your sleep if symptoms return despite treatment with CPAP
  • Find out how well surgery has worked to correct a sleep-related breathing disorder

What To Expect Before a Sleep Study?

  • Your doctor may ask you about your sleep habits and whether you feel well rested and alert during the day.
  • You may be asked to keep a sleep diary or sleep log. You’ll record information such as when you went to bed, when you woke up, how many times you woke up during the night, and more.

What To Bring With You?

  • Notes from your sleep diary or sleep log.
  • Pajamas and a toothbrush for overnight sleep studies.

How To Prepare?

  • You may need to stop or limit the use of tobacco, caffeine and other stimulants, and some medicines before having a sleep study.

What To Expect During a Sleep Study?

  • Sleep studies are painless.
  • It is usually are done at a sleep center
  • The room the sleep study is done in may look like a hotel room.
  • A technician makes the room comfortable for you and sets the temperature to your liking.
  • Most of your contact at the sleep center will be with nurses or technicians. You can ask them questions about the sleep study. They can answer questions about the test itself, but they usually can’t give you the test results.

During a Polysomnogram

  • Sticky patches and sensors called electrodes are placed on your scalp, face, chest, limbs, and a finger.
  • While you sleep, these sensors record your brain activity, eye movements, heart rate and rhythm, blood pressure, and the amount of oxygen in your blood.
  • Elastic belts are placed around your chest and abdomen. They measure chest movements and the strength and duration of inhaled and exhaled breaths.
  • Wires attached to the sensors transmit the data to a computer in the next room. The wires are very thin and flexible and are bundled together so they don’t restrict movement, disrupt your sleep, or cause other discomfort.

What To Expect After a Sleep Study

  • Once the sensors are removed after a polysomnogram (PSG) you can go home.
  • You won’t receive a diagnosis right away. Your primary care doctor or sleep specialist will review the results of your sleep study or sleep studies. He or she will use your medical history, your sleep history, and the test results to make a diagnosis.
  • It may take a couple of weeks to get the sleep study results. Usually, your doctor, nurse, or sleep specialist will explain the test results and work with you and your family to develop a treatment plan.
What Are the Risks of Sleep Studies?

  • Sleep studies are painless.
  • There’s a small risk of skin irritation from the sensors. The irritation will go away once the sensors are removed.
  • Although the risks of sleep studies are minimal, these studies take time (at least several hours). If you’re having a daytime sleep study, bring a book or something to do during the test.