What is a normal AHI? Normal sleep study numbers
Last updated: 2026-09-06
Quick answer
A normal AHI is under 5 breathing events per hour. Normal overnight blood oxygen (SpO₂) sits around 94–98%, and a low ODI means few oxygen-drop events. An AHI of 5 or more indicates sleep apnea — mild (5–15), moderate (15–30) or severe (30+). A doctor reads these numbers together with your symptoms.
Normal AHI
An AHI below 5 events per hour is considered normal in adults. From 5 up, obstructive sleep apnea is present and graded mild, moderate or severe.
Normal oxygen numbers
Healthy overnight SpO₂ is roughly 94–98%. The report shows your average and lowest oxygen; a low nadir (for example dips below 90%) suggests apnea is affecting your oxygen. A low ODI (few desaturation events per hour) is reassuring.
Reading the numbers together
No single number tells the whole story. A normal AHI with strong symptoms may still prompt further testing, while a raised AHI with big oxygen dips and back-sleeping clustering paints a clearer picture. That is why a physician interprets the full report.
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