Skip to Content



Polysomnography (PSG) is a sleep test to learn if you have a sleep-related breathing disorder (SRBD), such as obstructive sleep apnea.


Informed consent

is a legal document that explains the tests, treatments, or procedures that you may need. Informed consent means you understand what will be done and can make decisions about what you want. You give your permission when you sign the consent form. You can have someone sign this form for you if you are not able to sign it. You have the right to understand your medical care in words you know. Before you sign the consent form, understand the risks and benefits of what will be done. Make sure all your questions are answered.

Before your PSG test:

You will be given information about the test and what will happen. Healthcare providers will then clean your skin to put on the electrodes. Any of the following monitors may be used for your PSG test:

  • ECG: This test, also called an EKG, helps healthcare providers look for any problems in your heart. If you have an SRBD, your heartbeat may change during sleep because it does not get enough oxygen. Sticky pads are placed on your chest, arms, and legs. Each sticky pad has a wire that is hooked to a machine or monitor. Electrical activity in your heart muscle is recorded.
  • EEG: This test is also called an electroencephalogram. This test is done to see how your brain is working during the different stages of sleep. Electrodes will be put on your head. Each has a wire that is hooked to a machine. This machine prints a paper tracing of brain wave activity from different parts of your brain.
  • EMG: This test, also called electromyography, measures the electrical activity of your muscles. EMGs are used to check your leg and facial movements while you sleep.
  • EOG: This test, also called electrooculogram, measures your eye movements while you sleep. Electrodes are be placed near your right eyebrow and under your left eye.
  • Plethysmogram: This test monitors your chest and abdominal movement. Elastic belts are placed around your chest and abdomen to see how deep you breathe. This test also tells your healthcare provider how many breaths you take per minute and if you stop breathing.
  • A pulse oximeter is a device that measures the amount of oxygen in your blood. A cord with a clip or sticky strip is placed on your finger, ear, or toe. The other end of the cord is hooked to a machine.
  • Recordings: Recordings may be done while you sleep by a video, microphone, or both. This is done to hear how loud your snoring is and to see how you sleep. If a microphone is used, an electrode may be placed on your throat or neck.
  • Thermistor: This test uses a sensor to measure your nasal pressure. The thermistor will tell your healthcare provider how much airflow you have through your nose and mouth while you sleep.

During your PSG test:

Healthcare providers will monitor your sleep for the whole test. CPAP may be needed if your healthcare provider chooses to do a split night test. A CPAP machine is used to keep your airway open during sleep. With CPAP, you wear a mask over your nose and mouth or just your nose. The mask is held in place by soft elastic straps that go around your head. The mask is hooked up to the CPAP machine. The machine blows a gentle stream of air into the mask when you breathe. The stream of air helps to keep your airway open so you can breathe more regularly.

After your PSG test:

When the PSG test is over, the electrodes will be taken off. You may be able to take a shower if you choose to. You may be told when to follow up with your healthcare provider to get the results of your test. When you are ready, you will be able to go home.


Having an SRBD may make it hard to do normal activities such as work and school. SRBDs cause daytime sleepiness which may lead to car accidents or other injury. SRBDs that are not treated may cause more severe health problems. Untreated SRBDs may cause high blood pressure, heart disease, and stroke. You may need two or more PSG tests while healthcare providers treat your breathing problem.


You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Learn more about Polysomnography (Inpatient Care)

Associated drugs

IBM Watson Micromedex