Apnea-Hypopnea Index (AHI)

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Classify obstructive sleep apnea (OSA) severity.

Sleep Study Data

Number of Apneas

Number of Hypopneas

Total Sleep Time

Hours

Minutes

OSA Severity

AHI Score4.3events/h

ClassificationNormal

Severity Guide

< 5Normal

5 - 15Mild

15 - 30Moderate

> 30Severe

About this calculator

Overview

The Apnea-Hypopnea Index (AHI) is the standard metric used to determine the presence and severity of obstructive sleep apnea (OSA). It represents the average number of apnea (complete pauses) and hypopnea (partial reductions) events that occur per hour of sleep.

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Pro Tips

Include all events recorded during the study for an accurate index.
A split-night study may result in a shorter sleep time; ensure calculation reflects the exact duration.
AHI doesn't account for symptoms like daytime sleepiness; always treat the patient, not just the index.

Fun Facts

"An apnea is a pause in breathing for at least 10 seconds."
"A hypopnea is a partial blockage of air for at least 10 seconds with a drop in oxygen saturation (SaO2)."
"Untreated severe Sleep Apnea is linked to hypertension, stroke, and heart failure."
"AHI is typically measured during an overnight sleep study (polysomnography)."

Formula: AHI = (Total Apneas + Total Hypopneas) / (Total Sleep Time in hours).