Sleep apnea is a common sleep disorder caused when the muscles controlling soft tissues in the airway fail to keep the airway open when a person is asleep. The airway becomes obstructed resulting in suffocation until the person is awake enough to voluntarily control the muscles. This state of awakeness is usually very short (seconds long) and is not perceived by the person as interrupted sleep. The primary symptom of the disease is snoring, which is always unheard by the patient, but can disturb the sleep of anyone else sharing living space with the patient.
Obesity and alcohol use are the primary causes of sleep apnea, although it can affect anyone, even children. Obesity tends to obstruct the airway, while alcohol use reduces involuntary muscles reflexes that keep a sleeping person's airway open.
The usual treatment is lifestyle changes - loss of weight and abstaining from alcohol or other sedative drugs. However, not all patients have these risk factors. In these cases, the first resort of treatment is ensuring positive air pressure in the airways during sleep, usually through the use of a device that fits over the nose and provides a continuous positive flow of air through the airway through the night. This prevents the soft palate from blocking the airway when the person exhales.
However, serious cases of sleep apnea must be treated with surgery, generally by making the airway larger or reducing the mass of the soft palate.