Anyone can have sleep apnea—young, old, male, female, and even children. However, certain sleep apnea causes and risk factors have been associated with obstructive sleep apnea (OSA).
Sleep Apnea Causes
All of the muscles in the body relax during sleep. In people without obstructive sleep apnea, the throat muscles relax but do not block the airways. In patients with obstructive sleep apnea, the airways do become temporarily blocked or narrowed during sleep, reducing air pressure and preventing air from flowing normally into the lungs.
Certain physical characteristics of the face, skull, and neck can affect the size of the airway.
Large Neck. A large neck (17 inches or greater in men and 16 inches or greater in women) is a risk factor for sleep apnea. While some people’s necks are naturally larger than others, being overweight or obese can contribute to having a large neck.
Facial and Skull Characteristics. Structural abnormalities in the face and skull contribute to many cases of sleep apnea. These include:
- Soft Palate Characteristics. Some people have specific abnormalities in the soft area (palate) at the back of the mouth and throat that may lead to sleep apnea. These abnormalities include:Undersized or receding lower jaw or chin (micrognathia)
- Jutting lower jaw (retrognathia)
- Narrow upper jaw
- Enlarged tongue
- Enlarged tonsils
- The soft palate is stiffer, larger than normal, or both. An enlarged soft palate may be a significant risk factor for sleep apnea.
- The soft palate and the walls of the throat around it collapse easily.
Muscle Weakness. Abnormalities or weakness in the muscles that surround the airway can also contribute to obstructive sleep apnea.
Sleep Apnea Risk Factors
Gender. Obstructive sleep apnea is more common in men than in women. Men tend to have larger necks and weigh more than women. However, 45% of sleep study referrals are women and women tend to be misdiagnosed.
Age. Sleep apnea is most common in adults ages 40 – 60 years old. Middle age is also when symptoms are worse. Nevertheless, sleep apnea can affect people of all ages.
Family History. People with a family history of obstructive sleep apnea are at increased risk of developing the condition.
Obesity. Obesity is a particular risk factor for sleep apnea. Obesity can contribute to sleep apnea when fat deposits fill throat tissue.
Smoking. Smokers are at higher risk for apnea. Those who smoke more than two packs a day have a risk 40 times greater than nonsmokers.
Alcohol Use. Alcohol use may be associated with apnea. Patients diagnosed with sleep apnea are recommended not to drink alcohol before bedtime.
Medical Conditions Related to Sleep Apnea
Diabetes. Diabetes is associated with sleep apnea and snoring. It is not clear if there is an independent relationship between the two conditions or whether obesity is the only common factor.
Gastroesophageal Reflux Disease (GERD). GERD is a condition caused by acid backing up into the esophagus. It is a common cause of heartburn. GERD and sleep apnea often coincide. Research suggests that the backup of stomach acid in GERD may produce spasms in the vocal cords (larynx), thereby blocking the flow of air to the lungs and causing apnea. Apnea itself may also cause pressure changes that trigger GERD. Obesity is common in both conditions, and more research is needed to clarify the association.