There Are 3 Types of Sleep Apnea

Though it’s common, the condition often goes undiagnosed. Since most common and telltale symptoms of sleep apnea — such as snoring, pauses in breathing, and gasping for air — occur during sleep, many people may not even be aware that they are experiencing symptoms, so they go undiagnosed and untreated.

Each type of sleep apnea is characterized by many of the same hallmark symptoms, but the mechanism (or cause) of sleep apnea is somewhat different among each type.

First, What All Types of Sleep Apnea Have in Common

Because these awakenings are typically very brief, the person with sleep apnea may not even be aware that they are experiencing interrupted sleep. But the episodes can wreak havoc on the sleep cycle and prevent the person with sleep apnea from reaching the deep, restful phases of sleep. And that’s why people who have sleep apnea can experience significant exhaustion and drowsiness the next day, despite getting what they thought was a full night of sleep.

The throat muscles support the soft tissues in the back of the throat — such as the soft palate, the uvula, the tonsils, and tongue — so when those muscles collapse too much, those tissues can fall back into the throat, partially or completely blocking the normal flow of air in your airway. When the airway is blocked partially the person may start to snore, which is why this symptom is common in OSA. (It’s worth noting not everyone who snores has sleep apnea.)

When your brain senses that you aren’t getting enough oxygen, it signals your body to wake up enough so that you can reopen your airway, and you may gasp for air during the night. Simply put, having obstructive sleep apnea means that not enough air can get into lungs at night, and your brain wakes you up to breathe, says Robson Capasso, MD, chief of sleep surgery and associate professor of otolaryngology and head and neck surgery at Stanford University School of Medicine in California.

Research indicates that cases of obstructive sleep apnea have risen significantly in the last two decades. This is likely due to two main factors: Obesity (one of the most common risk factors for OSA) has increased dramatically; and there is more awareness about sleep apnea among doctors and the public at large, so more people are being screened and diagnosed, says James Rowley, MD, professor of medicine at Wayne State University School of Medicine in Detroit, and a member of the board of directors of the American Academy of Sleep Medicine (AASM).

Obstructive sleep apnea can be treated with a device to keep your airway open, such as a machine that pushes air pressure into your lungs through a mask that fits over your nose and mouth while you sleep, called continuous positive airway pressure (CPAP).

Other OSA treatment options include other breathing machines, mouthpieces designed to keep your jaw forward and keep your airway open, or surgery (in more severe cases) to remove tonsils or other tissue that could cause airway obstruction or move your jaw to open up your airway.

Your doctor may also advise you to lose weight and to avoid sleeping on your back, to prevent gravity from further pushing your tongue, tonsils, and other soft tissues in your throat into your airway.

Central sleep apnea is less common than obstructive sleep apnea. It can also be trickier to diagnose and treat. Unlike obstructive sleep apnea, which is caused by a mechanical problem that blocks the airway, central sleep apnea occurs because the brain is not sending the proper messages to the muscles that control breathing. “Central sleep apnea is caused by a neurological reason,” explains Dr. Capasso.

RELATED: Obesity and Heart Disease: What's the Connection?

In patients with complex sleep apnea syndrome, breathing problems persist even after the airway obstruction is addressed and treated, which means something besides the collapsing throat muscles are also contributing to the apnea.

But the researchers were not able to identify factors that influence risk for complex sleep apnea, and did not identify treatment options in this study. They concluded that additional research is needed to better define the condition and further study which treatments are most effective for treating complex sleep apnea.