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What does AHI represent?

  • Posted by: Jean Noel
  • Category: News
AHI

“AHI”, what does it mean?

Apnea-Hypopnea Index measures sleep apnea severity. The AHI is the sum of the number of apneas (pauses in breathing) plus the number of hypopneas (periods of shallow breathing) that occur, on average, each hour.

Working in collaboration with Dr. William C. Dement, Dr. Guilleminault established the apnea–hypopnea index, which is still in use today to characterize the presence and severity of sleep apnea.

To count in the index apneas and hypopneas, collectively called events, must have a duration of at least 10 seconds.

The AHI, as with the separate Apnea Index and Hypopnea Index, is calculated by dividing the number of events by the number of hours of sleep.

What does AHI represent?
Shows the different level of AHI for sleep apnea patients

From the rating chart here, we see that an index less that 5 is considered normal. For an Apnea-Hypopnea Index from 5 to 15 denotes mild sleep apnea. Fifteen to 30 is moderate, while a greater than 30 is considered severe.

  • AHI = sum of the number of apneas (pauses in breathing) plus the number of hypopneas (periods of shallow breathing) occurring, on average, each hour.
  • Apneas and hypopneas, collectively called events, must last at least 10 seconds to count as events.
  • The Apnea-Hypopnea Index is calculated by dividing the number of events by the number of hours of sleep.
Author: Jean Noel