Sleep Apnea Diagnosis

Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a breathing disorder occurs during sleep. OSA patients experience brief pausing of breath (apnea) during sleep. Apnea can occur as frequently as 20-30 times per hour, lasting for at least 10 seconds or more every time. Patients with less severe conditions may experience apnea a few times every hour.


Diagnosis of Sleep Apnea

See Your Doctor

If you have the symptoms of OSA, you should see your family doctor, a Respiratory Medicine or Otorhinolaryngology specialist for their professional advice. After preliminary assessment by your doctor, you will be recommended to go to a hospital for a detailed polysomnography(PSG) test.


PSG is usually performed during the night. Groups of sensors and probes will be attached over the body of the patient to record his/her stages of sleep, breathing pattern and blood oxygen level. The result will be used to diagnose OSA. If the patient is diagnosed negative for OSA, the doctor will investigate the cause of bad sleep quality or daytime sleepiness. Know more details

Titration Test

If the patient is diagnosed positive for OSA, he/she will be required to spend another night in the hospital for a pressure titration test. During the test, the titration machine will determine an opimal air pressure to prevent the patient from apnea by adjusting the pressure input into the airway of the patient through a mask.Know more details

Use of CPAP machines

Patients can select CPAP machines suitable for them and apply the prescribed pressure. Extended use of CPAP is the most effective treatment for OSA. Next to CPAP, use of mouthguards and surgery are alternative treatment for OSA.


What is PSG

A PSG is required to diagnose OSA. PSG is usually performed in hospital throughout the night, but may continue for a few nights because the patients may have difficulties in falling into sleep in the first night. During the test, over 10 groups of electrodes and cables will be attached to the body and the head of the patient to collect data for the following physiological conditions throughout the night:

  • Brain wave
  • Electrocardiographs
  • Breathing pattern
  • Blood oxygen level
  • Change of sleeping poses
  • Movement of chest and abdomen
  • Movement of limbs
  • Snore


What is Titration?

OSA patients need the help of CPAP machine to maintain a continuous airflow in their airway. Health care professionals use Titration Tests to determine the appropriate pressure patients should use for their home CPAP machines. The test lasts for the whole night and the patients will be required to wear a mask which is connected to a CPAP machine. The machine will deliver air of certain pressure through the nostrils into pharynx and larynx of the patient so as to open the obstructive tissues according to the condition of the patient’s airway. The machine will find an appropriate pressure to keep the patient breathe continuously.

After analyzing the Titration Test results, your doctor will prescribe a pressure for you to use with CPAP machines. The patient can then choose and buy a CPAP machine and apply the prescribed pressure. The report of Titration Test includes information of:

  • Duration of sleep
  • The pressure required to prevent apnea during sleep
  • Apnea condition after using the CPAP Machine
  • Saturated oxygen level when using the CPAP machine


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