Sleep apnea can be considered a serious sleep disorder that occurs when a person’s breathing is interrupted during sleep. Patients with untreated sleep apnea tend to stop breathing repeatedly during their sleep, sometimes hundreds of times. This means the brain — and the rest of the body — may not get enough oxygen and other serious complications could arise.
There are three types of sleep apnea:
- Obstructive sleep apnea (OSA): The more common of the forms of apnea, it is caused by a blockage of the airway, usually when the soft tissue in the back of the throat collapses during sleep.
- Central sleep apnea: Unlike OSA, the airway is not blocked, but the brain fails to signal the muscles to breathe, due to instability in the respiratory control center.
- Complex sleep apnea, as the name implies, is a combination of the two conditions. With each apnea event, the brain rouses the sleeper, usually only partially, to signal breathing to resume. In those with severe sleep apnea this can happen hundreds of times a night, often most intensely late in the sleep cycle during rapid-eye-movement (REM) sleep. As a result, the patient’s sleep is extremely fragmented and of poor quality. Meanwhile the disorder continuously reduces the oxygenation of the blood, further stressing the sleeper’s physical system.