Causes of apnea range from excess weight gain to neurodegenerative disease. Some sleep apnea causes are preventable, but others, such as the jaw’s bone structure, are unavoidable.
Sleep Apnea Risk Factors
Certain conditions increase the risk of sleep apnea. Men are twice as likely to develop sleep apnea as women, according to the Mayo Clinic (2010). In both genders, however, sleep apnea risk increases with age; sleep apnea is two to three times more common after age 65. Women see an increase in sleep apnea rates after menopause.
A family history of sleep apnea increases the risk of developing the disorder, suggesting genetic causes of apnea. However, as family members tend to share lifestyle and sleep habits, it’s possible a family history of apnea is linked to environmental factors.
High blood pressure increases the risk of sleep apnea. The two conditions can aggravate each other, as sleep apnea also contributes to high blood pressure.
Alcohol and sedative medication increases apnea risk as such substances relax the throat muscles. Smokers have an especially high risk of sleep apnea and are three times more likely to develop obstructive sleep apnea than nonsmokers, according to the Mayo Clinic (2010).
Obstructive Sleep Apnea
Obstructive sleep apnea causes the soft tissue at the back of the throat to collapse, blocking the airway. The collapsed airway triggers partial wakefulness as breathing restarts. The individual may not completely awaken, but the process disrupts sleep.
Excess weight is one of the most common causes of apnea. Extra fat in the throat narrows the airway, increasing the chance of airway collapse. People with neck circumferences in excess of 17 inches have an increased risk of sleep apnea. The sleep disorder is very common among football players, especially linebackers.
Other obstructive sleep apnea causes include overly large tongues and tonsils, nasal obstructions and bone structure that results in a narrowing of the airway at the mouth or throat. Some people have throat muscles and tongues that relax too much when they sleep, also resulting in obstructive sleep apnea.
Central Sleep Apnea
Central sleep apnea causes differ from those seen in obstructive sleep apnea. Central sleep apnea occurs when the brain fails to send the correct messages during sleep, causing short interruptions in breathing.
Conditions that affect the brain, and particularly the brainstem, are possible central sleep apnea causes. Strokes, polio, encephalitis and Parkinson’s and other neurodegenerative diseases can cause central sleep apnea.
Extreme obesity can cause central sleep apnea and obstructive sleep apnea. Spinal surgery complications or radiation therapy to the cervical spine are also causes of apnea. The cervical spine is the portion of the spinal cord directly below the skull.
Severe arthritis of the cervical spine is a possible cause of central sleep apnea. Central sleep apnea causes also include heart disease, especially congestive heart failure.
Mixed Sleep Apnea
Mixed sleep apnea occurs when both obstructive and central sleep apnea present together. Mixed sleep apnea causes are the same as the causes of obstructive and central sleep apnea.
Living Heart Foundation. (n.d.). Sleep apnea in professional football players. Retrieved August 16, 2010, from http://www.livingheartfoundation.org/sleep.pdf.
Mayo Clinic Staff. (2010). Sleep apnea. Retrieved August 13, 2010, from http://www.mayoclinic.com/health/sleep-apnea/DS00148.
National Heart Lung and Blood Institute. (2009). Sleep apnea. Retrieved August 13, 2010, from http://www.nhlbi.nih.gov/health/dci/Diseases/SleepApnea/SleepApnea_WhatIs.html.
National Library of Medicine. (2010). Central sleep apnea. Retrieved August 13, 2010, from http://www.nlm.nih.gov/medlineplus/ency/article/003997.htm.
National Library of Medicine. (2010). Obstructive sleep apnea. Retrieved August 13, 2010, from http://www.nlm.nih.gov/medlineplus/ency/article/000811.htm.