Sleep apnea is when a person stops breathing for 10 seconds or longer during sleep and sleep hypopnea is when a person has shallow breathing. Whether the disorder is mild, moderate or severe depends on the number of times a person experiences apnea or hypopnea per hour. If a disorder is to be defined as sleep apnea, the number of episodes per hour can be five or greater.
The most common sleep-disordered breathing condition is obstructive sleep apnea (OSA), which is caused by a blockage or narrowing of the airways in a person’s nose, mouth or throat. The obstruction occurs when the muscles that control the soft palate and tongue relax. However, bone deformities or enlarged tissues in the nose, mouth or throat are other causes of OSA. If you have enlarged tonsils, for example, the tonsils can press down on your airway when you lie down to go to sleep, which can lead to a partial or complete blockage. Additional factors that can increase the likelihood of OSA are certain medications, drinking alcohol before going to bed, obesity and sleeping on your back.