Apnea Index and the Severity of Sleep Apnea

How Many Apneas Per Hour Do You Have?

What is Apnea Index? How can you use apnoea index to discover how severe is your sleep apnea syndrome?

How sick is a person with sleep apnea disorder?

The sleep specialists need to answer these questions to decide on the most adequate treatment.

Apnea Index Description

Obstructive apnea is defined as cessation of nasal or oral airflow for at least 10 seconds. This one episode is called an apnea event. But if your airflow in and out of your lungs is reduced for at least 10 seconds, then you will have an hypopnea event.

Let's suppose you have 15 apnea events per hour of sleep. This means that you have an index of 15.

In conclusion:

• an apnoea index or AI shows the average number of apneas per hour of sleep.


• an hypopnea index or HI shows the average number of hypopneas per hour of sleep.


• an apnea and hypopnea index or AHI shows the average number of apneas and hypopnea per hour of sleep. Some doctors use the term of respiratory disturbance index or RDI, instead of AHI.

Another measurement used in sleep laboratory is the total number of apnea events during an entire night. In our example, you have 120 apneas in an eight-hour night.

Think about it! You wake up at least 120 times a night, without air, gasping and sweaty. And you will not even notice. It's obvious why are you so tired during the day!

People who read about Sleep Apnea Index also read about:

• Hypopnea


• New treatments for sleep apnea


• Why do people snore?

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