Sleep apnea is a sleep disorder characterized by pauses in breathing during sleep. Each episode, called an apnea, lasts long enough so that one or more breaths are missed, and such episodes occur repeatedly throughout sleep. The standard definition of any apneic event includes a minimum 10 second interval between breaths, with either a neurological arousal (a 3-second or greater shift in EEG frequency, measured at C3, C4, O1, or O2), a blood oxygen desaturation of 3-4% or greater, or both arousal and desaturation. Sleep apnea is diagnosed with an overnight sleep test called a polysomnogram, or a “Sleep Study”.
Sleep apnea is a common disorder that affects more than 18 million people in the United States. 
In many of these people, the condition is undiagnosed. OSA takes its name from the Greek word apnea, which means “without breath.” People with sleep apnea literally stop breathing repeatedly during their sleep, often for a minute or longer and as many as hundreds of times during a single night.
Symptoms of Obstructive Sleep Apnea (OSA) are:
- Frequent silences during sleep due to breaks in breathing (apnea)
- Choking or gasping during sleep to get air into the lungs
- Loud snoring
- Sudden awakenings to restart breathing or waking up in a sweat
- Daytime sleepiness and feeling unrefreshed by a night’s sleep, including falling asleep at inappropriate times
Causes and risk factors of obstructive sleep apnea:
When you have obstructive sleep apnea, your throat collapses during sleep, blocking the airway and preventing air from getting to the lungs. Generally, your throat muscles keep the throat and airway open.
Primary causes and risk factors of obstructive sleep apnea
- Being overweight or obese (although 50% of people with sleep apnea are not obese)
- Large tonsils or adenoids
- Other distinctive physical attributes (deviated septum, shape of head and neck, receding chin, enlarged tongue)
- Nasal congestion or blockage (from cold, sinusitis, allergies, smoking, etc.)
- Throat muscles and tongue relax more than normal during sleep (possibly due to alchohol or sedatives or age)
Treatments for obstructive sleep apnea may include:
Therapies
- Continuous positive airway pressure (CPAP). If you have moderate to severe sleep apnea, you may benefit from a machine that delivers air pressure through a mask placed over your nose while you sleep. With CPAP (SEE-pap), the air pressure is somewhat greater than that of the surrounding air, and is just enough to keep your upper airway passages open, preventing apnea and snoring.
Although CPAP is a preferred method of treating sleep apnea, some people find it cumbersome or uncomfortable. With some practice, most people learn to adjust the tension of the straps to obtain a comfortable and secure fit. You may need to try more than one type of mask to find one that’s comfortable. Some people benefit from also using a humidifier along with their CPAP system.
- Adjustable airway pressure devices. If CPAP continues to be a problem for you, you may be able to use a different type of airway pressure device that automatically adjusts the pressure while you’re sleeping. For example, units that supply bilevel positive airway pressure (BiPAP) are available. These provide more pressure when you inhale and less when you exhale.
- Oral appliances. Another option is wearing an oral appliance designed to keep your throat open. CPAP is more effective than oral appliances, but oral appliances may be easier for you to use. Some are designed to open your throat by bringing your jaw forward, which can sometimes relieve snoring and mild obstructive sleep apnea.
A number of devices are available from your dentist. You may need to try different devices before finding one that works for you. Once you find the right fit, you’ll still need to follow up with your dentist at least every six months during the first year and then at least once a year after that to ensure that the fit is still good and to reassess your signs and symptoms.
Surgery
The goal of surgery for sleep apnea is to remove excess tissue from your nose or throat that may be vibrating and causing you to snore, or that may be blocking your upper air passages and causing sleep apnea. Surgical options may include:
- Uvulopalatopharyngoplasty (UPPP). During this procedure, your doctor removes tissue from the rear of your mouth and top of your throat. Your tonsils and adenoids usually are removed as well. This type of surgery may be successful in stopping throat structures from vibrating and causing snoring. However, it may be less successful in treating sleep apnea because tissue farther down your throat may still block your air passage. UPPP usually is performed in a hospital and requires a general anesthetic.
- Maxillomandibular advancement. In this procedure, the upper and lower part of your jaw is moved forward from the remainder of your face bones. This enlarges the space behind the tongue and soft palate, making obstruction less likely. This procedure may require the cooperation of an oral surgeon and an orthodontist, and at times may be combined with another procedure to improve the likelihood of success.
- Tracheostomy. You may need this form of surgery if other treatments have failed and you have severe, life-threatening sleep apnea. In this procedure, your surgeon makes an opening in your neck and inserts a metal or plastic tube through which you breathe. You keep the opening covered during the day. But at night you uncover it to allow air to pass in and out of your lungs, bypassing the blocked air passage in your throat.
Removing tissues in the back of your throat with a laser (laser-assisted uvulopalatoplasty) or with radiofrequency energy (radiofrequency ablation) are procedures that doctors sometimes use to treat snoring. Although sometimes these procedures are combined with others, they aren’t usually recommended as sole treatments for obstructive sleep apnea.
Other types of surgery may help reduce snoring and contribute to the treatment of sleep apnea by clearing or enlarging air passages:
Nasal surgery to remove polyps or straighten a crooked partition between your nostrils (deviated nasal septum)
Surgery to remove enlarged tonsils or adenoids
Documentation: http://helpguide.org/
http://www.sleepdisorderchannel.com
