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AHI lookup: what does your number mean?
Enter an AHI and this AHI lookup places it on the right scale: diagnostic severity if it came from a sleep study, or residual AHI if it came from your CPAP machine. The two scales use similar numbers but answer different questions.
- About 1 minute
- Free, no sign-up
Free AHI lookup. Enter an AHI from a sleep study or your CPAP machine and see which band it falls in, what it means and what to check next.
What your result looks like
A sample result. Yours appears here the moment you finish, with what it means and what to do next. Every possible result is listed beside it.
Moderate
23/30
030
An AHI of 15 to under 30 is classed as moderate sleep apnea.
Fifteen to thirty events per hour before treatment. Positive airway pressure is a standard first-line treatment at this level.
- What is a good AHI on CPAP?
- Find a machine that fits your prescription
0–5Normal range
An AHI under 5 is in the normal range for adults.
Either side of 6Mild
An AHI of 5 to under 15 is classed as mild sleep apnea.
Either side of 6Moderate
An AHI of 15 to under 30 is classed as moderate sleep apnea.
Either side of 6Severe
An AHI of 30 or more is classed as severe sleep apnea.
Either side of 6Great
Under 5 on CPAP is the usual target for well-controlled therapy.
Either side of 6Mild
Your residual AHI is above the usual target of under 5.
Either side of 6Moderate
Your residual AHI is well above the usual target.
Either side of 6High
A residual AHI of 30 or more needs your clinician's attention.
Look up your number
Tell us where the number came from, then enter it. Signed-in users can pull it straight from their Apnealytics data.
What this tool does
The AHI lookup is for anyone holding an AHI and wondering what it means: a new sleep study report, a number on your machine's screen, or a figure in an app. It tells you which band the number falls in on the scale that applies.
It cannot diagnose sleep apnea or tell you whether your therapy is right. A sleep study AHI is one input to a diagnosis. A CPAP AHI is a machine estimate based on airflow alone.
How the score works
The two scales share cut-points but answer different questions.
| AHI (events/hour) | Sleep study: severity | On CPAP: Apnealytics band |
|---|---|---|
| Under 5 | Normal | Great |
| 5 to under 15 | Mild | Mild |
| 15 to under 30 | Moderate | Moderate |
| 30 or more | Severe | High |
Diagnostic severity describes how often your breathing was disrupted without treatment, measured per hour of sleep (lab) or recording (home test). Residual AHI describes what is left while you use CPAP, estimated per hour the mask was on. A severe diagnosis with a residual AHI of 2 means therapy is doing its job.
Reading your result
Normal or Great. Under 5. On a study, not sleep apnea by AHI. On CPAP, the usual target.
Mild. 5 to under 15. On a study, treatment depends on symptoms. On CPAP, look for a cause if it lasts more than a few nights.
Moderate. 15 to under 30. On a study, CPAP is a standard option. On CPAP, a pattern worth raising with your clinician.
Severe or High. 30 or more. On a study, follow your treatment plan. On CPAP, check for a large leak first, then contact your care team.
What to check after a high CPAP AHI
A single number tells you how many events, not why. Three things explain most changes:
- Leak P95. A poor seal can raise AHI and make the estimate less reliable.
- Event composition. A rise in central or unclassified events means something different from a rise in obstructive events.
- Usage. Short nights or long awake periods with the mask on change the denominator.
On the Apnealytics dashboard, all three sit beside your AHI, and Heads up flags a night that is unusual for you.
Sources
- AASM Task Force. Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques. Sleep, 1999.
- Berry RB et al. AASM Manual for the Scoring of Sleep and Associated Events. American Academy of Sleep Medicine.
- Patil SP et al. Treatment of adult OSA with positive airway pressure: AASM clinical practice guideline. J Clin Sleep Med, 2019.
FAQ
What is a normal AHI?
For adults, a diagnostic AHI under 5 events per hour is considered normal. From 5 to under 15 is mild, 15 to under 30 is moderate, and 30 or more is severe. On CPAP, the usual target for residual AHI is also under 5, but that number describes treated breathing, not a diagnosis.
Why is my CPAP AHI so much lower than my sleep study?
Because the machine is treating the events it counts. Your study measured breathing without pressure; your machine reports what is left with it. The machine also counts per hour of use and infers events from airflow only, so it is an estimate, not a lab measurement. A big drop is what therapy is meant to do.
Is an AHI of 5 on CPAP bad?
Not on its own. Five sits at the edge of the usual target, and nights vary. Look at your 7-night and 30-night averages. If the average stays above 5, check leak and event types, and raise it with your clinician at your next review.
Does the lookup use my own data?
If you are signed in to Apnealytics, you can fill the number from last night, your 7-night average or your 30-night average. The result then shows your leak P95, event mix and usage alongside. If you are not signed in, nothing you type is stored.
Can I use this for a child's sleep study?
No. Children are scored with different criteria and different severity thresholds. These bands apply to adults only. Ask your child's sleep specialist to explain their report.
Diagnosed and on CPAP? See if it's working.
Apnealytics reads your machine's SD card and shows residual AHI, leak and usage every night. Your first 30 nights are free.
