Sleep apnea can have many potential causes, most of which relate to problems with the anatomy of the upper airway. Sleep apnea is a chronic medical condition where the affected person repeatedly stops breathing during sleep. These episodes last 10 seconds or more and may occur hundreds of times during the night. The resulting dropped oxygen levels of the blood can lead to significant sleep disruption and serious consequences. It may occur secondary to obstruction of the upper airway, resulting in obstructive sleep apnea, or because of a failure of the brain to initiate a breath, called central sleep apnea.
Being overweight or obese is perhaps the major predisposing factor for sleep apnea. Being overweight likely contributes in two ways. First, when you are overweight extra fat tissue will build up throughout your body, including along your airway. This may lead to some narrowing -- especially in the throat -- that could make it more prone to obstruction while you sleep.
In addition, the extra pounds may serve as an external pressure that accomplishes the same thing. Imagine a 30-pound bag of sand sitting on your chest or stomach. It’s no wonder that this extra weight can disrupt your breathing. Individuals with large necks are especially at risk for apnea because the pressure is more direct.