What Causes Sleep Apnea? Lifestyle, Genetics, & Other Risks

Sleep apnea is a sleep disorder characterized by shallow or no breathing for short periods of time. It’s often referred to as “sleep-disordered breathing.”

Sleep apnea is dangerous because the brain and other parts of the body don’t get enough oxygen when breathing is interrupted, which may lead to lasting damage. It’s essential to have sleep apnea diagnosed and treated as quickly as possible.

Studies suggest that up to 24% of the US population has sleep apnea. Men are more than twice as likely to have sleep apnea than women. It’s estimated that 82% of men and 93% of women with moderate to severe sleep apnea remain undiagnosed.

What are the potential causes, and how can you spot sleep apnea’s symptoms? Here, we’ll unpack the reasons why this condition can occur.

Types of Sleep Apnea

There are 3 main types of sleep apnea:

  1. Obstructive sleep apnea (OSA) happens when the muscles of the throat relax so much that the tongue and other parts of the throat block the airway. Obstructive sleep apnea is the most common type of sleep apnea.
  2. Central sleep apnea (CSA) happens when signals from the brain don’t get to the breathing muscles correctly. Breathing isn’t fast or deep enough to properly exchange oxygen and carbon dioxide in the lungs.
  3. Mixed sleep apnea or complex sleep apnea is a mixture of obstructive sleep apnea and central sleep apnea.

What is the main cause of sleep apnea? The main cause of sleep apnea is airway narrowing or blockage during sleep. This most often occurs because soft tissue droops backward during sleep or because a patient has a narrow throat and airway due to their unique anatomy.

Causes of Obstructive Sleep Apnea

Obstructive sleep apnea happens when the airway is blocked during sleep. The muscles and soft tissues of the throat relax more than is typical, causing them to fall toward the back of the throat and block airflow. Relaxed throat muscles and tissues are also why patients often snore.

The soft palate (the non-bony part of the roof of the throat) can also play a role in restricting the airway. During sleep, the soft palate can change shape, either partially or entirely blocking the throat.

Obstructive sleep apnea happens most often when the patient is sleeping on their back. The effects of gravity compound the impact of relaxing throat muscles, making it even more likely the airway will be restricted or blocked.

Other causes of obstructive sleep apnea include:

  • Anatomical Abnormalities: People who have larger-than-normal adenoids and/or tonsils are at a higher risk of developing obstructive sleep apnea. Enlarged tonsils and adenoids make the airway narrower, restricting airflow during sleep.
  • Family History: Family history is also associated with sleep apnea. Your genetics can determine the shape of your mouth and throat, which affects your sleep apnea risk. Genetics can also affect your chances of developing other risk factors, like obesity.
  • Nasal Congestion: There’s some evidence that nasal congestion or obstruction can lead to sleep apnea. In these cases, patients usually take decongestants as part of their treatment.
  • Obesity: Most people associate obstructive sleep apnea with excess weight. Obesity can indeed put you at an increased risk of developing sleep apnea, but thin people can have sleep apnea, too.
  • Alcohol: Alcohol makes the throat muscles relax more than they would in normal circumstances, worsening or even causing sleep apnea.
  • Sedatives: Sedatives can also relax the throat muscles, making sleep apnea more likely.
  • Menopause: Post-menopausal women are at a higher risk of developing sleep apnea. They’re also more likely to have other risk factors like obesity and a larger neck circumference.

What causes sleep apnea to worsen? Any additional risk factors or causes of sleep apnea can cause sleep apnea to worsen. These include gaining weight, drinking alcohol excessively, or changes to the anatomy of the throat like tonsil enlargement.

What are 3 causes of sleep apnea? 3 primary causes of sleep apnea are a narrow airway or throat, obesity, and alcohol or medication that relaxes the throat muscles. These are all common causes of obstructive sleep apnea.

Causes of Central Sleep Apnea

The root cause of central sleep apnea is breathing signals from the brain not activating the diaphragm muscles in the chest, interrupting the regular breathing pattern. This happens because the brain doesn’t signal properly, or the muscles don’t respond appropriately to signals.

Central sleep apnea can be caused by:

  • Genetics: Some central sleep apneas are caused by genetic mutations, such as Congenital Central Hypoventilation Syndrome (CCHS).
  • Opioids: Opioid medications slow down breathing. Long-term use of opioids puts you at a much higher risk of developing central sleep apnea.
  • Heart Failure: Patients with heart failure often have different breathing patterns, which can lead to sleep apnea. Research suggests that they may be more sensitive to changes in carbon dioxide levels in the blood, causing apnea.
  • High Altitude: Being at a high altitude can also alter breathing patterns because oxygen is less available. This leads to central sleep apnea.
  • Neuromuscular Disorders: Neuromuscular disorders such as Parkinson’s disease and multiple sclerosis can affect the signals from the brain and how they’re received by the breathing muscles.

Causes of Mixed Sleep Apnea

Mixed sleep apnea is rarer than the other two forms of sleep apnea. One study found that only 6.5% of patients with obstructive sleep apnea also had central sleep apnea.

Perhaps the most significant cause of mixed sleep apnea is positive airway pressure (PAP) treatment in patients with obstructive sleep apnea. These patients are often treated with a continuous positive airway pressure or CPAP machine.

Long-term use of CPAP therapy can cause treatment-emergent central sleep apnea in obstructive sleep apnea patients. Treatment-emergent central sleep apnea is a form of mixed sleep apnea.

Symptoms of Sleep Apnea In Adults And Children

Many symptoms of sleep apnea are similar in adults and children. However, a few warning signs of sleep apnea show up uniquely in children, which parents may want to keep an eye on.

Sleep Apnea Symptoms In Adults

What are some of the symptoms of sleep apnea? Some of the symptoms of sleep apnea in adults are:

  • Excessive daytime sleepiness
  • Snoring
  • Dry mouth or sore throat when you wake up
  • Waking up in the middle of the night frequently, particularly if you feel like you’re choking or gasping when you wake up
  • Poor concentration
  • Depression and/or anxiety
  • Memory problems
  • Morning headaches
  • Sexual dysfunction
  • Night sweats

When the patient has more frequent and longer apneas, like patients with severe obstructive sleep apnea, they may experience more severe symptoms such as:

  • Very loud snoring (a bed partner may notice this before you do)
  • Long periods without breathing while sleeping
  • Severe fatigue causing significant disruptions at work, in school, or while driving

Sleep Apnea Symptoms In Children

Sleep apnea often goes diagnosed in children, but it can be very serious if left untreated. The most common symptoms of sleep apnea in children are:

  • Snoring
  • Mouth breathing
  • Bedwetting
  • Sleepwalking
  • Poor performance in school
  • Trouble paying attention and concentrating
  • Learning and/or behavioral problems
  • Memory problems

The symptoms of sleep apnea in children are the same as many symptoms of ADHD (attention deficit hyperactivity disorder). In fact, many children with sleep apnea can be misdiagnosed with ADHD.

Potential Complications of Sleep Apnea

Untreated sleep apnea can be very dangerous, leading to many serious health problems and medical conditions, including:

Many of these side effects occur because heart rate rises and blood oxygen levels plummet during apneic episodes. The heart gets overworked, affecting the heart muscle. The brain, organs, and body don’t get the oxygen they need, which may lead to long-lasting damage.

It can be very dangerous to drive a motor vehicle if you have sleep apnea. Patients with sleep apnea are much more likely to get in a motor vehicle accident because they feel drowsy. If you have sleep apnea symptoms and drive, please see a medical professional right away.

Sleep Apnea and Oral Health

Sleep apnea can also wreak havoc on your mouth and teeth. Many patients with sleep apnea breathe through their mouths, especially while sleeping. Mouth breathing can cause major dental problems over time.

Mouth breathing dries out the saliva in the mouth. Saliva is essential for keeping your teeth and gums healthy. It fights cavity-causing germs in your mouth and helps protect the lining of your mouth and gums.

Because it dries out your mouth, mouth breathing can lead to:

  • Cavities and tooth decay
  • Periodontal (gum) disease
  • Bad breath

Mouth breathing can also lead to:

  • Tonsil and adenoid hypertrophy (enlargement)
  • Tooth grinding
  • Tooth breakage

Patients with sleep apnea often grind their teeth as they sleep. In fact, most people who grind their teeth have sleep apnea. Tooth grinding can severely damage your teeth and even damage your jaw if left untreated. It can also cause a lot of pain in the mouth, jaw, and head as well.


If you or a family member have sleep apnea symptoms, you’ll want to speak to a biologic dentist. They’ll walk you through your treatment options and potentially refer you to a sleep specialist for a sleep study to determine the severity of your sleep apnea.

What is the treatment for sleep apnea? The treatment for sleep apnea can involve a combination of medical therapies and lifestyle changes like weight loss or avoiding alcohol. Oral appliances (mouthpieces) like the DNA appliance are minimally invasive and highly effective.

As you now know, sleep apnea can be very serious and should be treated promptly. As mouth and upper airway experts, we specialize in working with sleep apnea patients. We can help diagnose sleep apnea and create an individualized treatment plan for you.

If you suspect that you or a family member have sleep apnea, please make an appointment to see us at our East Hampton or Manhattan offices right away.

Dr. Gerry Curatola is a renowned biologic restorative dentist with more than 40 years of clinical practice experience.

He studied neuroscience at Colgate University and attended dental school at the New York University (NYU) College of Dentistry where he now serves as Adjunct Clinical Associate Professor in the Department of Cariology and Comprehensive Care.