💡 Key Takeaways
- Understanding AHI is Crucial: Your Apnea-Hypopnea Index (AHI) score is vital for diagnosing sleep apnea severity and evaluating the effectiveness of your CPAP therapy.
- Severity Levels: AHI scores range from normal (0-4.9 events) to severe sleep apnea (30+ events per hour). The higher the score, the more severe the condition.
- CPAP AHI Score: This score indicates how well you’re responding to CPAP therapy. A good AHI score on CPAP is usually fewer than five events per hour.
- Improving Your AHI: Factors like mask fit, lifestyle changes, and medication can affect your AHI score. Proper adjustments can lead to improvement.
- Monitor and Adjust: Regularly check your AHI score and consult your healthcare provider for any necessary adjustments to your CPAP therapy.
Understanding your AHI score is one of the most important aspects of any sleep apnea treatment, especially CPAP therapy. Also known as the Apnea-Hypopnea Index, this number determines the severity of your condition but also the effectiveness of your treatment plan.
So, what is AHI, and how does it relate to CPAP? Let’s talk about it!
Today, we’re explaining your AHI score and how it impacts sleep apnea. We’ll examine how it relates to events per hour on CPAP and how CPAP AHI score is measured. We’ll also cover important questions, including what is a good AHI score on CPAP and what it means if your CPAP AHI is reported as a decimal. Lastly, we’ll provide suggestions for improving your AHI score so you can get the most out of your CPAP therapy!
What Is AHI?
AHI stands for the Apnea-Hypopnea Index. It is the main system of measurement used to diagnose sleep apnea and refers to the average number of sleep apnea episodes you experience during each hour you are asleep. A higher AHI score indicates more severe sleep apnea.
What Does the Apnea-Hypopnea Index Mean?
The Apnea-Hypopnea Index (AHI) refers to the two possible types of sleep apnea respiratory events— apneas and hypopneas. The effect on your breathing can last a few seconds to more than a minute and occur multiple times throughout the night, leading to disrupted sleep and oxygen deprivation.
It is important to remember that AHI is primarily used for diagnosing Obstructive Sleep Apnea. For this reason, some people refer to these sleep apnea episodes as Obstructive AHI. If you have Central Sleep Apnea, you will still experience similar periods of apnea and hypopnea. However, most healthcare specialists will refer to such events as a Central AHI.
What Is an Apnea?
An apnea event is a near or total breathing pause that lasts longer than 10 seconds. During these episodes, the air you breathe in is reduced by at least 90%. Apneas usually occur when your airway becomes totally blocked by your tongue, soft palate, tonsils, or other surrounding structures.
What Is a Hypopnea?
A hypopnea episode is abnormally slow or shallow breathing that cuts your air supply by 30% or more. Each hypopnea episode must last at least 10 seconds. This event must result in a 3% drop in blood oxygen levels or a sleep disturbance (often called a sleep apnea arousal). Hypopnea arises when the mouth or throat muscles become so relaxed that they cause the airway to become partially blocked.
How Does AHI Affect Sleep Apnea Severity?
AHI typically varies depending on your sleep apnea severity. The higher your AHI score is, the worse your sleep apnea symptoms will likely be and the more likely you are to require higher continuous positive airway pressure settings. Below are the numbers that most experts reference when diagnosing sleep apnea.
|Normal||0 to 4.9 Events|
|Mild Sleep Apnea||5 to 14.9 Events|
|Moderate Sleep Apnea||15 to 29.9 Events|
|Severe Sleep Apnea||30+ Events|
How Is AHI Measured?
AHI is an average, meaning it is calculated by taking the total number of apneas and hypopneas you experience throughout a single night and dividing it by the number of hours you were asleep.
Your initial AHI score is provided to you following your first sleep study. However, that is not a set number that follows you throughout your entire sleep apnea journey. It changes often, even from night to night.
How to Calculate Your AHI
While sleeping for 7 hours and 20 minutes, you experienced 60 apneas and 120 hypopneas. Let’s figure out your AHI score!
- Find the Total Number of Sleep Apnea Events:
- 60 Apneas + 120 Hypopneas = 180 Total Sleep Apnea Events
- Figure Out the Amount of Time You Were Asleep:
- 7 Hours X 60 Minutes In an Hour = 420 Minutes
- 420 Minutes + 20 Minutes = 440 Total Minutes Spent Asleep
- Calculate How Many Sleep Apnea Events You Experienced Per Minute of Sleep:
- 180 Sleep Apnea Events ÷ 440 Minutes of Sleep = 0.27 Sleep Apnea Events Per Minute of Sleep
- Convert That Number to Sleep Apnea Events Per Hour of Sleep:
- 0.27 Sleep Apnea Events Per Minute X 60 Minutes In an Hour = 16.2 Sleep Apnea Events Per Hour of Sleep
- Check to See How Severe Your Sleep Apnea Was For That Night:
- 16.2 Sleep Apnea Events Per Hour of Sleep = Moderate Sleep Apnea
What is CPAP AHI?
Often referred to as CPAP events per hour, your CPAP AHI score tells your healthcare provider how well you respond to your current CPAP treatment plan. It indicates how many sleep apnea episodes you are experiencing while using your CPAP machine.
What Is a Good AHI Score on CPAP?
A good AHI score is usually fewer than five events per hour, but this can depend on your sleep apnea severity. People with mild sleep apnea may want to aim for less than two, while those with severe sleep apnea may shoot for under ten.
It is important to remember that CPAP therapy may not completely eliminate your sleep apnea episodes. While a CPAP AHI score of zero is excellent, most healthcare providers understand that this is not realistic for most people.
Ultimately, the goal is to simply reduce the total number of apnea episodes as much as possible so that we can limit the negative effects that sleep apnea has on your body.
How Does CPAP Measure AHI?
Your CPAP machine detects each sleep apnea event based on the guidelines provided by the Apnea-Hypopnea Index. These machines use algorithms to identify the lightest decrease in airflow, which is then compared to your recent “normal” breathing patterns. If that change is significant, it gets added to your total number of sleep apnea events per hour on CPAP.
Your CPAP report will most likely break down your events per hour data based on the type of respiratory event and its cause. Below are some categories you may see when checking out the readings on your CPAP machine.
- Apnea Hypopnea Index– AHI: Total number of events per hour on CPAP.
- Hypopnea Index– HI: Total number of slow or shallow breathing events per hour with CPAP.
- Apnea Index– AI: Total number of apneas per hour of CPAP therapy.
- Central Apnea Index– CAI: Total number of apneas caused by Central Sleep Apnea.
- Obstructive Apnea Index– OAI: Total number of apneas caused by Obstructive Sleep Apnea.
- Unknown Apnea Index– UAI: Total number of apneas that occur during an air leak, which affects the CPAP machine’s ability to determine whether they are central or obstructive apneas.
- Respiratory Effort-Related Arousal– RERA: This is the number of times you experience a small respiratory event that causes labored breathing that results in a sleep disturbance but does not quite meet the Apnea-Hypopnea Index requirements.
- Respiratory Disturbance Index– RDI: Total number of respiratory events. This combines your Apnea-Hypopnea Index score with your respiratory effort-related arousal score.
- Oxygen Desaturation Index– ODI: Total number of times per hour your blood oxygen levels drop by at least 3% for more than 10 seconds.
- Cheyne Stokes Respirations: This refers to the number of times your CPAP machine detects a specific pattern of breathing unique to a particular type of Central Sleep Apnea.
What Does 0.5 Events Per Hour Mean on CPAP?
Seeing a decimal on your AHI score is normal! Apnea-Hypopnea Index calculations are reported as an average and do not usually come out to perfectly rounded numbers. An AHI of 0.5 events per hour means that you are having one sleep apnea event every two hours.
Earlier, we calculated an AHI score for someone with 180 sleep apnea events over 7 hours and 20 minutes. That number came out to be 16.2, meaning that person would experience around 16 sleep apnea events for every hour. But every now and then, that number may have been closer to 17 or 18 breathing events in a single hour.
Improving Events Per Hour on CPAP
It can be very concerning to see that your AHI score is not as low as you would like it to be while undergoing CPAP therapy. Let’s discuss why this happens and what you can do about it!
Why Is My AHI Increasing With CPAP?
There can be several reasons why your reported CPAP events per hour are not going down.
- Mask Issues: If your CPAP mask is not fitted properly, it can lead to mask leaks, which are well known for impacting the effectiveness of your CPAP therapy. Additionally, some people accidentally remove their masks temporarily, causing the CPAP machine to record an AHI, even if one didn’t occur.
- Some Medications or Substances Impact Your Breathing: Sleep apnea is often aggravated by narcotic painkillers, muscle relaxers, sleep aids, or alcohol. Be sure to contact your doctor if you notice a change in your sleep apnea events per hour after drinking or taking a new medication.
- Development of Complex Sleep Apnea: Sometimes referred to as Treatment-Emergent Sleep Apnea, this rare condition arises when someone undergoing CPAP therapy for Obstructive Sleep Apnea also develops Central Sleep Apnea. Complex Sleep Apnea is very rare and usually requires changes to your CPAP treatment plan.
How to Lower AHI on CPAP
If you are still experiencing too many Apnea-Hypopnea Index events per hour, it may be time to make some changes! These can include lifestyle changes, adjusting your CPAP mask, and changing your sleeping position. In some cases, your air pressure setting may need to be adjusted.
- Make Some Lifestyle Changes: It is important to avoid things that can worsen your sleep apnea. Your doctor will likely encourage you to make some lifestyle changes, such as limiting your alcohol intake, avoiding smoking, and switching away from medications that may make it harder for you to breathe normally.
- Choose the Right Mask: Mask fit has a huge impact on whether or not your CPAP therapy will be effective. Be sure to choose a mask that meets your sleep apnea needs and adjust it correctly to avoid mask leak issues.
- Change Your Sleep Position: Did you know that sleeping on your back is the worst sleep position for recovering from sleep apnea? When on your back, your AHIs will naturally be worse because gravity works to pull your airway closed. By switching your sleeping position to your side, your machine will have to work less to keep your airway open.
- Replace Your Mask Cushion and Headgear: Your headgear and mask cushions develop wear and tear over time and must be replaced regularly. When you replace your CPAP mask equipment, you can get a better mask seal, reduce mask leaks, and allow more pressurized air to reach your airway.
- Talk to Your Doctor About Changing Your CPAP Pressure: If you have adjusted your lifestyle, CPAP equipment, and sleeping habits and are still experiencing AHI issues, it may be time to speak with your doctor about adjusting your CPAP pressure.
Frequently Asked Questions
What Is the AHI Range for Severe Sleep Apnea?
The Apnea-Hypopnea Index range for severe sleep apnea starts at 30 or more sleep apnea events per hour. In extreme cases, it can be over 100.
What Is a Good AHI for Mild Sleep Apnea?
If you are undergoing CPAP treatment for sleep apnea, experts suggest your AHI target should be less than 5, if possible. However, in cases of very mild sleep apnea, your doctor may encourage you to aim for an AHI score of 2 or less.
Will Changing My Mask Improve My AHI Score?
It is important to choose a mask that fits properly and suits your needs. If you have tried to adjust your existing mask and are still experiencing mask leak issues, or your AHI score is not improving, you may need to try a new mask in a different size or style.
How Is Apnea-Hypopnea Index (AHI) Used to Measure Obstructive Sleep Apnea?
The Apnea-Hypopnea Index is the measuring tool by which sleep specialists determine whether or not you fit the requirements for an Obstructive Sleep Apnea diagnosis. An AHI score of over 5 qualifies for at least mild sleep apnea. The higher your score, the more likely you will require CPAP therapy.
What Does 0.7 Events Per Hour Mean on CPAP Machine?
A CPAP AHI score of 0.7 is great news! If you are undergoing CPAP treatment for sleep apnea, your therapy goal is most likely less than 5 sleep apnea events per hour. An AHI score of less than 1 means you are experiencing less than 1 sleep apnea event per hour on CPAP.
Is an AHI Score the Same Thing as myAir Score?
The Apnea-Hypopnea Index plays a key role in determining the severity and treatment of your sleep apnea. If you are undergoing CPAP therapy for your sleep apnea, it is very important to monitor your CPAP AHI score because it is a good indicator of whether or not you are responding well to treatment. By keeping your total events per hour under 5, you’ll be on the path toward better sleep health. And if you’re struggling to get that number under control, we hope you can use some of these tips so that you can continue to benefit from your CPAP treatment plan!