How is Sleep Apnea diagnosed?

In addition to checking with the person affected, to find out what symptoms they have, the doctor may also ask the person’s partner to describe the symptoms they have seen and heard. Sometimes the person themselves may be unaware that they have a problem, but their partner may have actually seen them having an episode of apnoea. 

The doctor will also assess the type of sleepiness a person is experiencing, to work out whether sleep apnoea is a possible diagnosis. In sleep apnoea, daytime sleepiness occurs when a person does not want to sleep, for example when driving or when working. 

The Epworth Sleepiness Scale (ESS) is a way of measuring how likely a person is to fall asleep, in a particular situation during the daytime. It involves the patient filling out a questionnaire, and helps the doctor to find out how severe the condition is. 

A number of tests can be carried out to help diagnose sleep apnoea: 

  • A polysomnogram. This involves an overnight stay in a sleep laboratory, and records the apnoea/hypopnoea index, how much and how loudly a person is snoring, and their sleeping position. 
  • Visual observation of sleep. This enables doctors to check whether the patient is having breathing difficulties, if their breath is pausing for long periods and they are waking up. 
  • Pulse rate and the amount of oxygen in the blood. This helps detect if breathing has been disrupted. 

Other signs of sleep apnoea that tests may detect include abnormal heart rhythm or large increase in blood pressure, during the night. 

Part of the diagnosis process will involve ruling out other causes of daytime sleepiness. These can include sleep deprivation, depression, narcolepsy (a condition involving an irresistible urge to sleep at any time of day), or neurological conditions such as Parkinson’s. 


Information source: NHS Direct Online Health Encyclopedia, 2005