Sleep Apnea Tests & Diagnosis

If you have symptoms of sleep apnea, your doctor may ask you to have a sleep apnea test in a sleep disorder center. This often includes a polysomnogram.

A sleep study or polysomnogram (PSG) is a multiple-component test that electronically transmits and records specific physical activities while you sleep. The recordings are analyzed by a qualified sleep specialist to determine whether or not you have sleep apnea or another type of sleep disorder.

If sleep apnea is determined, you may be asked to return to the lab for further evaluation in order to determine the best treatment option.

What to Expect

On the night of your sleep study, you will be assigned to a private bedroom in a sleep center or hospital. Near the bedroom will be a central monitoring area, where the technicians monitor sleeping patients.

You will be hooked up to equipment that may look uncomfortable. However, most people fall asleep with little difficulty.

Equipment Used

Surface electrodes will be put on your face and scalp and will send recorded electrical signals to the measuring equipment. These signals, which are generated by your brain and muscle activity, are then recorded digitally. Belts will be placed around your chest and abdomen to measure your breathing. A bandage-like oximeter probe will be put on your finger to measure the amount of oxygen in your blood.

Other Tests and Equipment Used

• EEG (electroencephalogram) to measure and record brain wave activity
• EMG (electromyogram) to record muscle activity such as face twitches, teeth grinding, and leg movements, and to determine the presence of REM stage sleep. During REM sleep, intense dreams often occur as the brain undergoes heightened activity.
• EOG (electro-oculogram) to record eye movements. These movements are important in determining the different sleep stages, particularly REM stage sleep.
• EKG (electrocardiogram) to record heart rate and rhythm.
• Nasal airflow sensor to record airflow.
• Snore microphone to record snoring activity

Reviewed by The Sleep Medicine Center at The Cleveland Clinic.