All sleep apnea is characterized by repeated interruptions in breathing, but the underlying cause varies. There are three main types:
Obstructive Sleep Apnea This is the most common form of sleep apnea, and it occurs when there is a partial or complete obstruction of the airway, says Neeraj Kaplish, MD, the director of sleep laboratories at the University of Michigan in Ann Arbor.
When we sleep, the muscles in our body, including those in our throat, naturally relax. Normally, the airway remains open enough for air to enter freely during sleep. But in cases of obstructive sleep apnea, your airway is too narrow (sometimes because you were born with a thicker neck and narrower airway, and other times because body weight creates extra fat deposits in the throat), and when you relax your muscles in your sleep, the tissues in the back of your throat can block your airway.
This airway blockage can cause loud snoring, snorting, or gasping for air during sleep (though not everyone with obstructive sleep apnea snores, and not everyone who snores has sleep apnea).
Central Sleep Apnea This type of apnea occurs when something goes awry with the brain’s normal signaling to muscles that control breathing in the body, causing breathing to repeatedly stop or become very shallow.
Unlike obstructive sleep apnea, which is caused by a physical blockage, central sleep apnea is a neurological problem, says Robson Capasso, MD, a professor of otolaryngology and head and neck surgery at Stanford University School of Medicine in California.
People who have central sleep apnea often have an illness or condition that affects the brain stem, which is the area of the brain that controls breathing. Health conditions linked to central sleep apnea include stroke, heart failure, kidney problems, or a brain lesion or disorder.
Certain medications that interfere with how well the brain sends signals to muscles, such as sedatives, opioids, or benzodiazepines, can also play a role in central sleep apnea, says Dr. Capasso.
Complex Sleep Apnea Syndrome Complex sleep apnea happens when someone has both obstructive sleep apnea and central sleep apnea at the same time.
People who have this type of sleep apnea often seem at first to only have obstructive sleep apnea, but when they’re treated for that condition and symptoms don’t improve as they should, doctors will suspect that central sleep apnea is also present.
