I. What is polysomnography? Polysomnography is an important screening technique in today’s sleep medicine, and is considered the “gold standard” in the world of sleep research for diagnosing various sleep disorder-related diseases. What is the purpose of polysomnography? This test can objectively evaluate the quality of sleep and sleep structure by monitoring the patient’s sleep EEG, EEG, EMG, nasal and oral airflow, oxygen saturation, snoring, chest and abdominal movements, leg movements, etc., which can be used for the diagnosis of various sleep disorders and help to provide targeted treatment for patients with different sleep disorders. The diagnosable sleep disorder diseases are: insomnia, sleep apnea syndrome and other sleep disorders (narcolepsy, sleep terrors, episodic sleeping sickness, restless legs syndrome, etc.). Third, what is the operation process of polysomnography? Polysomnography is performed from 20:00 that night to 7:00 the next morning. The skin is first cleaned and then the sensor components such as EEG, EYE, Jaw EMG, ECG, blood oxygen saturation, respiratory motion are connected. Turn on the computer, enter the patient information and perform data acquisition. Fourth, what are the precautions for polysomnography monitoring? 1. Do not take a nap at noon on the day of monitoring, please bring your own pajamas and pajama pants. 2. Do not drink alcohol or tea, coffee, cola or other beverages on the day of monitoring. If you are taking medication for a long time, please consult your clinician if you want to stop taking medication. 3. Please have a young family member accompany you if you are younger than 18 years old or older than 65 years old. 4. Please take a shower before the monitoring, and do not use hair and skin care products after the shower. 5. Male patients should shave on the day of monitoring.