Understanding Mild, Moderate & Severe Obstructive Sleep Apnea (OSA)

Obstructive sleep apnea (OSA) can be diagnosed as mild, moderate, or severe. What does that mean, and what is the recommended treatment method for each level of severity?


It’s important to treat Obstructive sleep apnea (OSA) to avoid serious risks to your health. Once you’re diagnosed with OSA, treatment options depend upon the severity of your sleep apnea. Pre-existing health conditions and risk factors to your health also play a role in deciding upon an effective course of treatment. 

So – how do you determine how severe your sleep apnea is, and what are the treatment options available?


The AHI – a measurement system called the apnea-hypopnea index – measures the number of breathing pauses that you experience each hour that you sleep. In other words, this scale totals up the number of apnea episodes (characterized as a complete suspension of breathing lasting 10 seconds or more) and hypopnea episodes (partial losses of breath lasting 10 seconds or more) that you experience during the night. The resulting figure is then divided by the number of hours you slept. 

Essentially, your AHI will tell you the average number of times your breathing is interrupted per each hour that you sleep. The severity of your obstructive sleep apnea (mild, moderate, or severe) is measured using this scale.

Mild obstructive sleep apnea (OSA) is indicated by an AHI between 5 and 15

Moderate obstructive sleep apnea (OSA) is indicated by an AHI between 15 and 30

Severe obstructive sleep apnea (OSA) is indicated by an AHI greater than 30 (more than 30 episodes per hour)

Mild OSA

Getting diagnosed with mild sleep apnea means that you experience fewer breathing interruptions per each hour of sleep than someone diagnosed with moderate or severe sleep apnea. However, mild OSA doesn’t necessarily mean that you’re experiencing minimal symptoms. Treatment options are largely determined based upon severity of symptoms (snoring, daytime sleepiness, and high blood pressure, to name a few) and comorbid conditions, including but not limited to stroke, diabetes, and hypertension.

Moderate OSA

Moderate sleep apnea occurs when the AHI indicates a higher number of breathing interruptions during the night than those that occur with mild sleep apnea. Common moderate sleep apnea signs and symptoms typically can include:

  • Excessive daytime sleepiness (also known as hypersomnia)
  • Morning headaches
  • Snoring
  • Nighttime gasping/choking/coughing
  • High blood pressure
  • Frequent urination during the night
  • Restless sleep (or difficulty staying asleep)
  • Dry mouth or sore throat when you wake up
  • Feelings of irritability, depression, or mood swings
  • Decreased libido
  • A larger neck size (characterized by the American Association of Oral and Maxillofacial Surgeons as greater than 17″ in men, and greater than 16″ around in women)

While on the surface, common moderate sleep apnea symptoms don’t look much different than the list of symptoms for mild or even severe sleep apnea, the difference is apparent by how pronounced your symptoms are, and how many of them are presenting together.

Severe OSA

Of all OSA severity levels, severe sleep apnea is characterized by the most breathing interruptions per each hour of sleep. The list of signs and symptoms for severe sleep apnea are similar to those of mild and moderate OSA. However, as with mild vs. moderate sleep apnea, severe OSA is differentiated by the most pronounced symptoms and the large number of them that exist together. Common comorbidities, among them diabetes and heart disease, are connected to severe sleep apnea. Recent studies have even shown that people with severe obstructive sleep apnea may be at much greater risk for fatal events like cancer.

Treating Mild To Moderate OSA With SomnoDent® Therapy

The primary non-surgical treatment option for severe sleep apnea is continuous positive airway pressure (CPAP), where pressurized air is emitted through a mask to prevent mouth or throat tissues from obstructing the airway. While CPAP may also be an option for treating mild to moderate obstructive sleep apnea, clinical studies have shown up to 20% of OSA sufferers chose not to start on CPAP, and up to 50% of CPAP patients have quit using it within one year. If you’ve tried wearing a CPAP mask and stopped or decided that CPAP is not for you, you are not alone – and you have options. 

SomnoDent® therapy may be just as effective as CPAP if you have been diagnosed with mild or moderate OSA. Oral appliances, like our SomnoDent® Avant, move your jaw and tongue forward while you sleep to open up your airway and treat your sleep apnea. Compared with wearing a CPAP mask, wearing a SomnoDent® Avant is comfort on a completely different scale. You’ll feel this from the moment you place it in your mouth; it glides onto your teeth, gently cradling and supporting each tooth. With SomnoDent® oral appliance therapy, there are no masks, and there is no noise, no hose, and no device to which you have to connect.

It’s so important to treat your OSA – however severe it may be. When left untreated, obstructive sleep apnea significantly increases the risk of health issues including cardiovascular disease, diabetes, and pulmonary hypertension and stroke. Untreated sleep apnea also increases the likelihood of motor vehicle and industrial accidents to occur, caused by excessive daytime sleepiness and cognitive decline—both of which are leading causes of mortality in U.S. adults.

For mild to moderate obstructive sleep apnea, a mouthguard like an oral appliance, made precisely to fit your mouth shape and your teeth, can help you get a comfortable night’s sleep. Talk to your Sleep Physician or Family Practitioner about SomnoDent®. While CPAP is a very effective treatment for OSA – particularly for severe OSA – it is only most effective if it is used consistently.

Start your journey to a healthier, happier you here: https://somnomed.com/en/find-a-clinic/





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