A polysomnogram or PSG is a sleep study used to identify sleep disorders. There are four types of sleep studies:
- Diagnostic Overnight PSG – During this study, a variety of things are monitored, including your heart rhythm, oxygen levels, breathing patterns, and limb movement.
- Diagnostic Daytime Multiple Sleep Latency Test (MSLT) – An MSLT is used to identify narcolepsy and assess the degree of daytime sleepiness, as well as how quickly you fall asleep during the day in a quiet environment. The test is also used to determine how long it takes for you to enter the REM sleep stage as well as how often. An MSLT is typically conducted the morning after a Diagnostic Overnight PSG.
- Two-Night Evaluation PSG and CPAP Titration – On the first night of the test you will be monitored and evaluated. If you are diagnosed with sleep apnea, you must return to the sleep center or hospital the next night so the technician can determine how much continuous positive airway pressure (CPAP) is needed to treat your condition. CPAP is a common treatment for sleep apnea. The device delivers a constant stream of air pressure through a nasal mask to keep your airway open during sleep.
- Split-night PSG with CPAP Titration – If you are diagnosed with moderate or severe sleep apnea during the first half of the study, during the second half the technician will determine the amount of CPAP pressure necessary to treat your condition.
Frequently Asked Questions
What Can I Expect During my Sleep Study?
Your sleep study will be conducted in the private room of a hospital or sleep center. The technicians will hook you up to the necessary equipment and monitor you while you sleep.
What Happens During a Sleep Study?
During the study, the technician will place electrodes on your scalp and face. These electrodes will send electrical signals generated by your brain and muscle activity to the equipment. The signals are recorded digitally. The technician will put belts around your chest and abdomen to monitor your breathing. A probe is placed on your finger to assess the level of oxygen in your blood.
What Happens During a Home Sleep Study?
If your physician recommends a home sleep study, you will be referred to a sleep specialist who can decide if it is right for you. Generally, home sleep studies are only used to diagnose OSA. If this method is ideal, you will receive a device to take home, along with instructions for how to use it. You must return or mail the device to the office the next day. The results are interpreted and you will be scheduled for a follow-up appointment to discuss treatment options.