Sleep apnea is a type of disordered sleeping where an individual’s breathing during sleep becomes slower and shallower, or even pauses entirely, for a period of time as short as several seconds or as long as a few minutes. Because of the reduced awareness experienced by someone who has been woken up from a deep sleep, many people with this disorder do not realize what is happening to them at night – the breathing problems are more likely to first be noticed by someone else sleeping in the same room.
A doctor may also arrive at an apnea diagnosis by way of the patient’s other complaints. Because the drop in oxygen levels during an apnea event triggers the brain to wake up and resume normal breathing, patients with sleep apnea do not rest well even if they think they are getting eight hours of shut-eye each night. Daytime exhaustion, difficulty focusing at work, headaches, and moodiness are all common side effects that may cause a care provider to take notice.
Once apnea is suspected to be at play, it can be confirmed with a formal sleep study, or polysomnogram. During a polysomnogram, several factors are measured, including the patient’s respiratory effort and oxygen levels – if five or more instances of disturbed sleep happen per hour, then sleep apnea is diagnosed.
Sleep apnea is caused by one of two factors. The first, and far more common, is a blockage in the airway that prevents normal airflow when supportive muscles relax during sleep, causing obstructive sleep apnea (OSA). Because the tissues that line the airway are soft and collapsible, they are susceptible to being compressed without that muscular support.
Obese patients are at risk for this type of apnea, as the extra weight can cause airway obstruction. Other risk factors include frequent tonsil or adenoid infection, Down syndrome, and palate or nasal surgery. This is the type of sleep apnea associated with loud snoring, as the airway vibrates when air squeezes past the obstruction.
Less commonly, sleep apnea results from a problem in the brain’s self-regulation system. In central sleep apnea (CSA), the brain fails to signal the body to breathe at a regular rhythm, causing pauses in respiration that result in decreased oxygen levels. In a few cases, patients may suffer from both forms of sleep apnea at the same time – a condition referred to as complex, or mixed, sleep apnea.
For mild cases, behavioral changes can help to reduce the number of apnea events that occur. Alcohol and certain drugs (muscle relaxants, sleeping pills) should be avoided, as they can increase the muscle slackness that contributes to the problem.
Sleeping on one’s side, rather than on one’s back, can also help relieve the pressure on the obstructed airway. Another option for those whose apnea is relatively mild is to get a specialized oral appliance that will hold the jaw in position and prevent the airway from collapsing during sleep.
If these methods aren’t enough, a patient can also be treated with a continuous positive airway pressure (CPAP) device, which directs a flow of air into the patient’s throat by way of a mask worn over the face. (The device works slightly differently in the case of central sleep apnea, where positive and negative air pressure alternate to help the patient both inhale and exhale.)
In the most extreme cases where other treatment attempts have failed, doctors may resort to surgery to reshape or stiffen the tissue in the airway so that obstruction is less likely to occur. While this is the most invasive option, it has up to a 95% success rate in helping patients achieve a normal night’s sleep.