Sleep Apnea Severity by AHI
The apnea hypopnea index (AHI) counts apneas and hypopneas per hour of sleep. It is the standard way to grade obstructive sleep apnea. Adults and children use different cutoffs because healthy children have very few breathing events during sleep.
| Population | Severity | AHIevents per hour |
|---|---|---|
| Adult | Normal | Under 5 |
| Adult | Mild | 5 to under 15 |
| Adult | Moderate | 15 to under 30 |
| Adult | Severe | 30 or more |
| Child | Normal | Under 1 |
| Child | Mild | 1 to under 5 |
| Child | Moderate | 5 to under 10 |
| Child | Severe | 10 or more |
Notes
- The AHI depends on how hypopneas are scored. The AASM recommended rule uses a 3 percent oxygen drop or an arousal; Medicare requires the 4 percent rule for coverage decisions.
- Home sleep tests usually divide by recording time, not sleep time, giving the respiratory event index (REI), which can underestimate severity.
- Pediatric bands vary slightly between sources, and diagnosis in children also weighs symptoms such as snoring, behavior and growth.
- Severity on its own does not decide treatment; symptoms and other health conditions matter too.
Frequently asked questions
Is an AHI of 5 to 15 something to treat?
It can be, particularly with symptoms such as daytime sleepiness, insomnia or high blood pressure. Medicare covers CPAP at an AHI of 5 to 14 when certain symptoms or conditions are documented.
What AHI should I see on CPAP?
Many clinicians aim for a machine reported residual AHI under 5 events per hour. Report persistently higher values to your care team.
Is the RDI the same as the AHI?
No. The respiratory disturbance index also counts respiratory effort related arousals (RERAs), so it is equal to or higher than the AHI.
Sources
More reference tables
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