Sleep apnea is a sleep disorder in which a person’s breathing is interrupted during sleep. Approximately 18 million Americans have sleep apnea, though many are not diagnosed with the sleep disorder. Oftentimes the person who suffers from sleep apnea is not even aware their breathing is stopped or slowed during sleep; rather, they are told about their condition by others who witness it. They may also suffer from symptoms of sleep apnea without knowing that is what they derive from. People with sleep apnea often exhibit “excessive daytime sleepiness,” moodiness, depression and a decrease in alterness. A polysomnogram (or sleep study) allows a sleep doctor or technician to diagnose the condition.
Sleep apnea can be classified in three different forms: obstructive sleep apnea, central sleep apnea and complex or mixed sleep apnea. Of the three, obstructive sleep apnea is the most common form of sleep apnea. Obstructive sleep apnea occurs when the windpipe collapse during sleep, blocking airflow. Once the brain recognizes that the blood oxygen level is falling, the person wakes up enough to tighten up the muscles and open the airway. Those with soft tissue and low muscle tone around the windpipe (often due to obesity) are at a high risk for obstructive sleep apnea. Daytime sleepiness, interrupted sleep and snoring are all symptoms of this form of sleep apnea.
Central sleep apnea occurs when there is an imbalance in the brain’s respiratory control centers during sleep, causing an uneven respiratory rate which in turn causes the sleeper to cycle between apnea and hyperpnea. They start and stop breathing with no sign that they are struggling to breathe. When they regain their breath, their breathing may be faster in an effort to absorb more oxygen and rid the body of excess waste gases. This is sometimes referred to as Cheyne-Stokes respiration.
When people exhibit both of these forms of sleep apnea, it is referred to as “complex or mixed sleep apnea.” Central apnea can sometimes develop if a case of obstructive sleep apnea is severe or chronic.
Treatment depends on the type and severity of the sleep apnea. Mild cases may be treated with behavioral therapy, such as changing sleeping position or avoiding alcohol, cigarettes or sleeping pills. There are also dental appliances that can be used. CPAP machines are by far the most common form of sleep apnea treatment. Surgical treatment may also be a possibility.