Apnea-Hypopnea Index (AHI) 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.
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.
From the AHI rating chart here, we see that an index less that 5 is considered normal. For an Apnea-Hypopnea Index (or AHI) from 5 to 15 denotes mild sleep apnea. Fifteen to 30 is moderate, while a greater than 30 AHI 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 AHI is calculated by dividing the number of events by the number of hours of sleep.
What does a Central Apnea Chart look like since that number is not included in the AHI number?
Central apneas are indeed calculated in the AHI. Central apneas are still apneas
Central apneas are indicated by the non-obstructive apneas.
Most of you have minor AHI readings. After two years of CPap I still have around 40 AHI despite using several pressure settings. I think my doctor realizes I have central apnea and will put me on bipap. I’ve always used a full mask. I sleep better but at age 74 I’m not getting better.
Hi all.
My AHI was 15 when i was at the sleep lab. 6 months on cpap. Its down to 1
Does that mean the cpap is doing its job? Or that i no longer have sleerp apnea? Ie do u ever stop usding tgs cpap? Thasnks. Liam
You sound like me! I have struggled with discouragement about those very issues of the AHI not yielding
I too need a full mask due to my mouth opening even though I generally breathe through my nose. What mask do you use? I have respironics F30
i started on a bi-pap machine 30 days ago. i had a terrible time for nearly the whole month in tryat ing to make the full mask work. I started calling to complain. I even went back in to the provider to see if the mask fit. finally, the manager, a respiratory therapist heard my pleas and called. she was at my house within the hour and gave me a different mask which has worked 100%. In the last 10 days, i have had 100% mask fit. The AHI is up and down and i dont know what makes the difference in higher or lower, but i think i am sleeping better and will hopefully improve as time goes by. i no longer dread putting on the machine and i no longer have red marks and pain from the ill-fitting mask. do not settle for an inferior fitting when you can get relief if the techs will only take the time that this manager did with me
Paula, it will take time for your apneas to start to decline. Your brain is still getting used to having air at night. I started my bipap last April, and after about a month, I was still getting 13 apneas an hour, but more alert and awake during the day. After a couple more months it dropped to 10, and after 8 months, I now average around 6.5 per hour. Still having good nights and bad, but that is part of the process. Hang in there.
It’s different from person to person. The first night I used my nasal only mask, I dove under 5 apneas per hour, and it’s been there ever since. Some nights I hit .5 apneas. Been using almost a month now. Before the machine, I was getting 40+ an hour.
Maybe try the “Ramp: feature if you have it on your machine.
I am on Philips Respironics Smart Auto CPAP since 1 month.
Do not find find much improvement.
Hi! I know this is an old thread, but can I ask what mask it is that you used that worked so well? Struggling over here. Thanks, and hope it’s still working well for you!
I’ve tried many different masks and struggled for a decade. The last one I tried was the “ResMed AirFit” and it’s been amazing! It’s a full face mask so you don’t have to worry about mouth breathing (I’d thats an issue for you). I hope this helps. Best of luck!
I have issues with the full mask tried the AMARA VIEW it lays just on the tip of the nose and covers the mouth but is much more comfortable because it doesn’t lay on the bridge of the nose
The Air touch mask is absolutely amazing. I highly recommend it. It has a great cushion and if you do NOT tighten it too much it leaves no red marks on your face. I highly recommend it.
I have very thick hair and it is hard to keep the mask in place what can I do?
Have you got longer hair? I keep my hair in a bun at night because it’s long and I’ve got a lot of hair, Baby fine so it’s slippery too. If not long enough for a bun I’m not sure what else may help. Have you contacted the place you got it from? They may have tips to help too.
me as well. I use a hair tie
I put my hair in a small pony tail and put the straps underneath. This way the straps don’t need to be as tight.
Put your hair in a high twist or bun at night and use that to help anchor the straps
Paula, I have a similar story except for the solution! No one there to help out.
I need a full face mask, too. Would you please let me know what mask you find perfect?
If so, thanks!
What mask are you using?
Different one Airfit f20 Air touch f 20 Air Fit F30 Air Fit N10 and N20
What is the difference between AHI and RDI (respiratory disturbance index). I did some basic research and it seems like RDI is considered “more accurate” but the clear differences are not elucidated very clearly. Any small clarifications would be greatly appreciated.
The RDI includes all the elements of the AHI plus “respiratory-effort related arousals (RERAs).” These are events where respiration is more difficult, but doen’t meet the criteria for the three factors included in AHI: viz., obstructive apneas, non-obstructive apneas, and hyponeas (reduced airflow below 80%, but not apnea).
My son (14) is now on Cpap his ahi is 2.5 which is “borderline for pediatric and normal for adult
He is a big 14 yr old !
After using the Cpap machine since July 16, he stays awake during the day now and has energy !
Prior to this he would come home from school everyday and take a 2 hour nap because he was exhausted from not “sleeping” at night
So for me the AHI means nothing as far as “normal” etc goes
as for my son it has changed his daytime tiredness to being able to do what other teens do and not taking a 2 hour nap EVERYDAY and then going to bed at 8:00 p.m. because he is still wiped out
As far as masks he tried the pillow mask and prefers the mask that goes over just the nose .
Is .5 and 5 the same measure? What does it mean when your number increases from .5 to 1.0? The decimal point is confusing. Where do these numbers fall on the chart from normal to severe?
It’s simple if you sleep 2 hours but only have one event during that two hours it will show up as point five or if you see point five and you slept 8 hours that means you had four events if you slept 8 hours and only had two events it would show up as .25
I have sleep apnea my machine is set on 8 but my air pressure was drying out my nose so i call where i pickrd up machine and she told me to turn it up and i put it on 4 the air pressure is this right
You should never adjust your air pressure you should only be adjusting your humidity if your air pressure is set to 8 you should not change it you should discuss it with your doctor however if you called and they told you to turn it up they were more than likely speaking about the humidity level and that you can adjust on your own my machine comes set to 4 standard or by default I actually turned it up to 5 to get a little more humidity to stop B from drying out this is a good setting for me
No wonder you’re not getting enough air with [lack of] punctuation like that…
Who cares about punctuation BEN ??????????? Enough question marks BEN ????????????????
Don’t you let Joseph get at you Ben.
Us ‘Grammar Police’ have a job to do. i.e. Protecting the English language from language terrorists such as him.
He (aggressively) reacts in the manner he does because he is one of those disadvantaged by not understanding. For him, it’s a defensive mechanism.
Actually, Bill, it’s “We grammar police,” rather than “Us grammar police.” Sorry to be picky, but as your post was about grammar, and this phrase is the subjective part of the sentence, I couldn’t let that go. 🙂
I suggest you to buy Philips Dreammaker with Humidifier attached to it. I bought this machine, fully Auto Pressure, I feel how beautiful the human invention is! I have Bluetooth attached to my mobile phone, Morning you just need to synchronise to get the data overnight, take a screenshot and store day by day in your phone in a separate folder.
I got the same few weeks back and within a day i was sleeping a sound sleep. I can monitor my sleep on the app.Its a very good machine and would surely recommend
Agreed on the Dream Mapper App by Phillips. No need to take screenshots. The App does it all, and even better with the ability to run reports you can then export to PDF and email to your Respiratory Therapist.
I was diagnosed with sarcoidosis about 7 years ago. I immediately fought against EXTREME fatigue. My pulmonary doctor recently told me that the sarcoidosis has been in remission for a couple of years now. I went and had a sleep study done. It revealed that I had 131 episodes an hour. Oxygen dropped as low as 60 and I stopped breathing up to 32.5 seconds. The doc said I am basically not sleeping at all. I got my CPAP machine and the next morning I felt so refreshed. It’s scary to think about how long my cells may not have had an opportunity to rejuvenate. I pray that any damage can be reversed with dedicated use of the CPAP machine.
congrats on the progress!!
Your results are very close to mine, and I also felt better after the 1st night. I’ve been had sleep issues all my life. In addition, I’ve been diagnosed with A.D.D and had been medicated as an adult. Now that I am using the machine, I’m so focused, aware, present, alert, etc.. I wonder if I really had A.D.D. Maybe instead of meds, I needed air!
You are right.. it is scary!
Now I look forward to using it at night.
I received a nasal mask, and was asked if I wanted a chin strap. I was told if I snored and breathed through my mouth, it wouldn’t do any good. I took the chin strap, but went without the first night (last night). My AHI over 10 hours was 3.9, so I’m thinking I don’t need to use it. What do you think?
If you are breathing through your mouth and your mouth is extremely dry when you wake up I would recommend the chin strap. You will know you are breathing through your mouth if it is dry. Hope this helps.
I breath through my mouth often at night due to nasal passages that easily get stuffy. My doctor prescribed me a mask that goes over my mouth as well.
I use a nasal mask, because I have a facial hair.
I do get an occasional dry mouth from what I call hurricane events… when I wake up because my mouth was open. I have dry mouth and nostrils. I usually end up sneezing the next morning.
I use a chin strap, trained myself to keep my mouth closed, and not I do not use it full time.
If I have a stuffy nose, or cold, then I use the strap. I crank up the humidifier, and basically use the cpap as a personal humidifier. It’s the best thing when you have a cold. You sleep.
Great comments here and I agree with all that’s been said. I usually don’t have a problem sleeping on my side, but if I roll on my back that’s when I have the “hurricane syndrome” and my mouth drops open. Totally dry in the morning.
So when I roll on my back now I grab a pillow and hug it up under my chin. Works for me… might not work for everyone….
If one’s AHI is 2.5 events per hour, what does the decimal point *(.5) represent? Is this reading considered low/medium/high?
A number below 5 is “normal”, but lower (like 2.5; i.e. 2 and a half) is better.
If you had 5 events in two hours, your AHI would be 5/2=2.5 which is considered normal.
Is the reading of 2.5 for events per hour considered low/medium/or high?
What does the decimal ( . 5 ) represent?
I’ve had my CPAP machine since 2003 & use it nightly. My insurance company now requires a sleep study showing AHI of 15 or more before they’ll pay for a new machine. After using the machine for so long I am sure hoping my sleep study will show 15 or more AHI. My first study records are no longer available.
Your reading is excellent. Less than 5 is considered normal. Good for you!!
The .5 is the result of the math – total apnea events during your night sleep divided by total hours slept.
The company I work for has a sleep study clinic at 3 of our terminals. Once you get picked to do the study you’re certain to get a cpap. My average ahi is less than 2 over a 7 day period. It’s a racket.
I recently changed from a nasal mask to a full face mask. The reason was I was getting a dry mouth . However my API was running from .1 to 4.0 now with the full face mask it has be 11.0 to 12.0 – can you tell me what is causing this
Suggest you ask your MD.
Do you have a humidifier attached? If yes, increase the setting for dry mouth. The nasal mask is better. Also, use a heated tube. Your earlier readings were great.is your CPAP machine auto. If yes, it should automatically adjust the air pressure.
It seems like with the full mask the pressure is not adequate.
Due to various nasal problems, it is getting increasingly harder to wear a mask. I have tried 6 different ones, but none are right. As I have not only apnea but also hypopnea (low oxygen) does anyone know if the oral devices help the hypopnea?
Suggest you ask your MD.
Go see a ENT. I was having very little success with all different types of mask. ENT did a CAT scan of my sinuses and found that they are nearly closed. Going in for a balloon procedure end of July that he assures me I will see great results with my cpap afterwards.
Just starting My therapy it’s been 4 days. I wake up my sinuses are horrible and puffy eyes
You should contact the supplier of the equipment to advise you on this… you need the humidity level adjusted to a lower level.
Your CPAP provider should have advice.
I’ve had my CPAP machine for 18 months. I wear a nose mask and tape my mouth at night. Still get a dry mouth! Still struggling to get a reading below 9. I’ve also had sinus and cough on and off, especially in Winter. I won’t give up but it’s frustrating. Any idea of what else might help?
I was put on CPAP for Atrial Fibrillation. My AHi was between 15 and 25. My doctor moved me to BIPAP machine set inhale 19 and 14 exhale. My AHI is now aroune 1 to 4 a night. I usually have either 0 or 1 obstructive apneas (versus 25-30) but I have @ 10 central Apneas a night ( as low as 6 and as high as 13). Is that good or am I supposed to eliminate the central apeas?
In for sleep study after several years on CPAP and my AHI was 86! My Dr comment was how are you still alive ! Am considering implant InspireSleep device, Anyone out there have any experience with InspireSleep?
I have an AHI if 5-15 I used a CPAP with 100% compliance for over 15 years. After 7-8 hours of sleep I still wake tired and my legs feel tired. I have a new Dreammaker machine.
Any one else experiencing this?
Yes. I am tired even with my CPAP. Recently my AHI ranges from 4 to 8. That does not sound too bad but it is still at times debilitating. I can only function with prescription stimulants. Next week I am getting a jaw advancement surgery so I will forever cured.
Where can I buy the mask
I just rec’d the Bpap setup and just finished my third night . I am having issues trying to get used to it, the mask keeps letting air escape so I tried to tighten the straps but then that was a bit irritating so I returned them to the original setting. I have to pretty much sleep on my back to allow the mask to function properly (less air escaping) while my normal position is on my side. I also wake with dry mouth and pronounced bags under my eyes. I downloaded the app and wonder if you can explain the following AHI details that I see on the app from last night
Total clear airway Apneas 64
Total obstructive Apneas 28
Total Hypoapneas 17
This would help me understand what these mean.
Thank you
The N20 nasal mask works great for me and I have a mustache.
My average AHI is 1.25 based on a report I generated from my CPAP provider. My highest AHI was between 2.5 and 3.75 which happened just two times in 90 days. Beaded on the chart I don’t have sleep apnea but according to my last sleep study I have it.
What happens to the brain and heart when you have sleep apnea? I was just diagnosed with mild sleep apnea, averaging 11 an hour. I experience palpitations and was recommended to take this test. But, I don’t fully understand the connection. Thanks so much.
Am I the only person who absolutely cannot sleep with the mask? I have had my machine for 3 months. I have both masks, the full face one and the nasal one. I just can’t sleep. After a few hours I give up and pull them off. The longest I have made it is 4 hours twice. Usually average around 2. I know I should wear it, but when I have to get up to go to work in 3 hours and I need to sleep, I just give up. I can’t sleep for several reasons: the mask is either too tight or keeps leaking, it dries me out on the highest humidity, underneath the mask keeps itching, you name it! I have insomnia and I rarely hit REM sleep anyway, so I’m kind of sunk.
I just started CPAP DreamStation about a week or two ago with setting of 10cm and ramp setting of 4cm for 45 minutes. The pressure seems too much and having hard time. I took both Tylenol PM and melatonin for bot parts of sleep studies since i get insomnia a lot. I have read many articles stating sleep aids can cause inaccurate results. The pressure makes me panic. Using CPAP is also making me have severe flashbacks and nightmares from being on life support twice this year. I am going back and forth between 3 different mask – Dreamwear gel nasal, Dreamwear full face, and Amara View. I keep taking them off in my sleep so i have to stay awake to meet adherence requirements for insurance. Anyone have an opinion of which of the masks is best or if anything will help my anxiety? I still worry about results since using sleep aids during testing.