What Is Mild Obstructive Sleep Apnea?

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Mild obstructive sleep apnea, according to the American Academy of Sleep Medicine, is the least-advanced type of obstructive sleep apnea (OSA). OSA is a sleep disorder that causes apneic events where breathing repeatedly stops and starts during sleep. OSA is considered a potentially serious disorder that can lead to adverse health effects.

People with mild OSA have sleep apnea that isn’t as interrupted as moderate to severe OSA. But because the condition is mild, it might be hard to know if you have it or for your healthcare provider to diagnose you with the condition.

Keep reading learn about mild obstructive sleep apnea, its signs, and symptoms, the risks associated with it, how it is different than more severe types, and how it is managed and treated.

CPAP therapy

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Types of Sleep Apnea  

Sleep apnea includes three serious sleep disorders where your breathing is interrupted while you sleep. People living with untreated sleep apnea stop breathing repeatedly in their sleep. When breathing is stopped, your brain and the rest of your body don’t get enough oxygen, which will affect your health over time.

There are three types of sleep apnea: obstructive sleep apnea, central sleep apnea, and complex sleep apnea:

  • Obstructive sleep apnea (OSA) is the most common of the three types of sleep apnea. It causes airway blockages when the soft tissues in the back of the throat collapse while you sleep. OSA is classified based on severity.
  • Central sleep apnea doesn’t result from a blocked airway. Instead, the brain fails to send the proper signals to the muscles that control breathing.
  • Complex sleep apnea is a distinct type of sleep-disordered breathing that is classified as central sleep apnea and presents in people similarly to OSA. It is usually discovered during initial treatment with a continuous positive airway pressure (CPAP) device after a person has been diagnosed with OSA. It might also be diagnosed during a sleep study when CPAP therapy is applied.

Obstructive Sleep Apnea Classified by Severity

Obstructive sleep apnea causes apneic events that reduce blood flow to the brain. When this happens, the brain gets a signal to partially awaken because the body needs to breathe.

After you wake up, you might experience loud gasping, choking, or snorting sounds because you are taking breaths to fight the obstruction. Once the breath is taken and the brain returns back to sleep mode, the process starts up again. This process might occur a few times a night or up to 100 times, depending on the severity of the apnea.

OSA is classified as mild, moderate, or severe.

  • Mild OSA: People with mild OSA have 5–14 breathing apneic events in one hour.
  • Moderate OSA: With moderate OSA, a sufferer will experience 15–30 episodes in an hour.
  • Severe OSA: The person will experience 30 or more episodes in an hour.

Even though mild sleep apnea causes fewer interruptions than moderate or severe OSA, 5 to 14 interruptions in breathing per hour are still a lot for your sleep to be interrupted and for you to stop breathing. 

Mild Sleep Apnea Symptoms

A person is given a diagnosis of mild sleep apnea based on an overnight sleep study called a polysomnography. Polysomnography records blood oxygen levels, brain waves, breathing patterns, eye movement, heart rate, leg movement, sleep stages, snoring, and more.

If you haven’t taken a sleep study and your symptoms are mild, it might be harder for you to know you are having sleep issues. But it is important to know what symptoms mild sleep apnea might cause because some of them can have a serious effect on your health over time.

By having this information, you can bring it to the attention of your healthcare provider who can assess you to determine the source of fatigue, sleep problems, and other symptoms.

People with mild apnea might snore. While snoring usually isn’t cause for any alarm, consistent and loud snoring is a sign of sleep apnea. Of course, not everyone who snores has sleep apnea.

Sleepiness is another common symptom of mild sleep apnea. People with mild sleep apnea don’t realize how much their sleep is being interrupted at night. All these interruptions can cause you to feel sleepy throughout your day.

Sleepiness can also cause you to have low energy and drowsiness, and might affect your cognition (i.e., thinking, reasoning, etc.) 

High blood pressure is also common with mild sleep apnea. This is because when oxygen levels fall, brain receptors are triggered. They send messages to the blood vessels to increase oxygen to the heart and brain so that the body can keep doing its job.

The increase in blood flow leads to pressure on the walls of blood vessels, elevating blood pressure. For this reason, people with OSA will experience high blood pressure. High blood pressure can increase your risk for a heart attack or a stroke.

A new OSA guideline from the American College of Cardiology (ACC) and the American Heart Association (AHA) describes cardiovascular disease as a risk factor in people with high blood pressure. It also considers OSA as a secondary cause of high blood pressure, including resistant hypertension.

Resistant hypertension is high blood pressure that doesn’t respond to treatment and requires multiple medications to keep blood pressure at acceptable levels. Resistant hypertension is usually secondary hypertension or has no identifiable cause. 

Additional sleep apnea symptoms that someone with mild sleep apnea might experience include:

  • Apneic events, usually witnessed by a sleep partner
  • Concentration troubles
  • Decreased libido
  • Erectile dysfunction
  • Gasping or choking during sleep
  • Insomnia: A sleep disorder that affects falling asleep and causes other sleep issues, including repeated awakenings
  • Irritability and other mood changes
  • Memory problems
  • Morning headaches
  • Nocturia: Frequently waking up at night to urinate
  • Non-refreshing sleep

Sleep apnea, regardless of its severity, can lead to sleep deprivation, and lack of sleep has far-reaching health consequences. Because sleep apnea can affect oxygen balance in the body, untreated sleep apnea can put you at risk for many very serious conditions.


The causes of mild OSA are the same as they are for moderate and severe OSA. These might include:

  • Anatomical characteristics: This might include things like the size and position of the jaw, neck, tongue, tonsils, or other tissues in the throat that might affect airflow.
  • Being a smoker: Smoking is commonly linked to obstructive sleep apnea although the mechanisms are not fully understood.
  • Being overweight: Being overweight is a risk factor for OSA and a leading cause of OSA. This is because obesity can contribute to the narrowing of the airway.
  • Family history: If you have close family members with the condition, it is more likely that you will develop OSA.
  • Hormone conditions: OSA seems to be associated with two hormone abnormality conditions. Hypothyroidism and acromegaly can both lead to OSA by causing tissue swelling in the airways or contributing to obesity. Hypothyroidism causes an underactive thyroid while acromegaly causes excess growth hormone. 
  • Nasal congestion: People who struggle to breathe through their noses because of persistent congestion are more likely to have OSA.
  • Sedative use: People who use sedatives, including alcohol, have an increased risk for OSA. This is because sedatives make it easier for the throat to relax and the airway to become obstructed.
  • Sleep position: People who sleep on their backs might experience tissue collapses that affect the airway and cause a blockage.

Diagnostic Challenges of Mild OSA

Obstructive sleep apnea is diagnosed based on the number of respiratory sleep disruptions per hour of sleep during an overnight sleep study. The more sleep interruptions you have the more severe the sleep apnea is. Interestingly, according to Harvard Medical School, most people with OSA fall in the mild category.

Unfortunately, most studies seem to focus on moderate and severe instances of sleep apnea, which doesn’t really give healthcare providers a lot of instruction when it comes to diagnosing mild sleep apnea. And if severity doesn’t correlate with symptoms, a diagnosis of mild OSA might not be considered.

But diagnosing OSA is vital because according to the National Heart, Lung, and Blood Institute, undiagnosed or untreated sleep apnea can lead to serious health complications, including heart attack, diabetes, cancer, and cognitive and behavioral disorders.

Generally, a diagnosis of OSA starts with complete medical history. Your healthcare provider will ask you about daytime sleepiness, if you snore, your sleep habits, and the quality of your sleep. They will also examine your head and neck to look for physical signs of sleep apnea.

A polysomnogram is usually done if your practitioner decides your sleep issues warrant further testing. Additional testing might be done depending on the results of the sleep study. 


When people hear the word “mild” as it relates to OSA, they think they don’t have a lot to worry about. But even mild OSA can still affect your life.

Untreated mild apnea could cause apneic events, snoring, and grasping while you sleep, which can lead to long-term adverse health effects and problems with daytime sleepiness, both of which are life-altering.

There isn’t a lot of agreement or information on whether mild sleep apnea should be treated and how it should be treated. Two articles going back to 2007—both published in the Journal of Clinical Sleep Medicine—debate treating versus not treating mild OSA.

The first piece argued that mild OSA does not require continuous positive airway pressure (CPAP) therapy and that there is no benefit to using a CPAP machine for treating mild sleep apnea. The second piece argues that mild OSA should be treated with CPAP therapy because even mild symptoms can adversely affect a person’s health.

But newer research does recommend treating mild sleep apnea with CPAP therapy. A study in 2020 published in The Lancet found that just three months of CPAP could improve the quality of life for people with mild OSA.

If you have mild sleep apnea, it is possible your healthcare provider might recommend a CPAP machine. They might also suggest other treatments including:

  • Weight loss: According to the Cleveland Clinic, even a 10% weight loss can reduce the number of apneic events for most people.
  • Exercise: In addition to weight loss, regular exercise might be helpful for getting a good night’s sleep. Exercise can increase your energy and improve your heart rate.
  • Avoid tobacco: If you smoke, it is a good idea to quit. Quitting smoking might reduce snoring and your risk for serious health conditions associated with both sleep apnea and smoking, such as high blood pressure and heart disease.
  • Oral appliances: Dental appliances that prevent the tongue from blocking the throat or that support the jaw can minimize airway collapse, and reduce apneic events and other sleep apnea symptoms.
  • Positional therapy: Different sleeping positions (i.e., sleeping on your side) might reduce the number of hourly apneic events you experience while you sleep.
  • An Inspire hypoglossal nerve stimulator: This therapy involves a device implanted under to skin. At night, it is turned on to stimulate the muscles, so they don’t cause airway collapse.
  • Surgery: Surgical procedures might help people with sleep apnea who have excessive or abnormal tissue that obstructs airflow through the nose or throat. This might include a deviated septum or large tonsils. According to Cleveland Clinic, surgery becomes an option when CPAP and other measures fail to help.

If you have mild sleep apnea, CPAP is always an option. Talk to your healthcare provider about how CPAP therapy might help you to get a better night’s sleep. Your practitioner can give you a prescription and let you know how CPAP therapy works.

A Word From Verywell

You should talk to your healthcare provider if you experience daytime sleepiness or if you consistently struggle to sleep well at night. They can request a sleep study and create a treatment plan that fits your lifestyle. 

While mild sleep apnea might not be as disruptive as moderate or severe OSA, it can still affect your health and your quality of life. Sleep problems are always worth getting checked out because treatment can reduce the number of apneic events you experience and help you to get better, more refreshed sleep. 

17 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Lana Barhum
Lana Barhum has been a freelance medical writer since 2009. She shares advice on living well with chronic disease.