Twenty percent of Americans have trouble sleeping. Millions of them have a common condition called obstructive sleep apnea, a respiratory disorder marked by upper airway obstruction, which causes brief interruptions of breathing during sleep. The condition is more common in men, among those who are overweight and in older age groups.

Andrew Krystal, M.D., director of the Sleep Research Laboratory and Insomnia Program at Duke University Medical Center, says early diagnosis and treatment of sleep apnea is important, since it may be associated with several life-threatening medical problems if left untreated.

These include heart failure, stroke and pulmonary hypertension. He recommends an overnight sleep evaluation to help diagnose the cause of the problem.

According to Krystal, there are several typical warning signs for sleep apnea. He explains that someone may show one or more of these symptoms, but that the signs by themselves are not absolute indications that the condition is present.

“If someone is sleepy during the day, if they’re loud snorers, if they are known to stop breathing by someone observing them, if they have morning headaches or dry mouth, high blood pressure that doesn’t respond to treatment or depression that doesn’t respond to treatment, these are signs that the disease sleep apnea may be present and are reasons to get evaluated.”

For many people with mild cases of sleep apnea, losing weight can help relieve obstruction of the airway and improve sleep. For more severe cases, the most common treatment is C-PAP, or continuous positive airway pressure, which blows air into the nasal passages via a mask or nose plugs, keeping the airway open and unobstructed. A sleep disorder specialist can help determine the correct air pressure for the device and ensure the correct fit. In some cases, a facial deformity, enlarged tonsils, large tongue or some other tissue may be obstructing the airway, requiring a surgical procedure.

For many people (and their sleep partners), a C-PAP machine is a godsend. “People say, ‘This is a miracle. I can’t believe it,’” adds Krystal. “With those people, you’d have to fight pretty hard to get their sleep apnea device away from them.”