There are a number of potential causes of sleep apnea, which is often a chronic condition. One kind of sleep apnea is central sleep apnea, which occurs when the area of the brain that controls breathing fails to send proper messages to the muscles that control breathing. This type of sleep apnea is often caused by certain medicines or in people with medical conditions.
The more common type of sleep apnea is obstructive sleep apnea, which is caused by a blockage of the breathing passage or a collapsed airway. With the airway blocked, it is difficult for air to travel through the airway to the lungs. Pauses in breath occur as the physical obstruction keeps air from traveling freely through the airway. A snoring sound results as air is squeezed through the breath's obstructed pathway. Not all snoring is caused by sleep apnea, so one should not confuse snoring and sleep apnea although many people who snore do suffer from sleep apnea.
Children with enlarged tonsils are also at risk of experiencing obstructive sleep apnea as the inflamed tissue blocks the breathing passage. Small structural features along the air passage, such as the airways of the nose, mouth or throat, can result in sleep apnea as the small size may serve as obstacles to breathing.
Also, during sleep, the muscles in the throat and along the air passageways relax. Overweight individuals are often affected by obstructive sleep apnea as the excess tissue weighs heavily on the airway, causing it to collapse. According to the National Heart Lung and Blood Institute, more than half of people with sleep apnea are overweight. The condition is also more common in males than females, among those with a family history including sleep apnea, and the chances of experiencing sleep apnea becomes more common with age.