CPAP devices aid breathing for sleep apnea patients.

Sleep apnea causes abnormal pauses in breathing that can last 10 to 30 seconds, sometimes longer, during sleep. Each pause is called an apnea. It can lead to daytime sleepiness and concentration problems.

An estimated 20 million Americans suffer from sleep apnea, and it has become more common. Although most people don't know they have it, the affliction can be diagnosed with a sleep test.

Kristen Archbold is an assistant professor at the University of Arizona College of Nursing and a sleep expert who works with both children and adults with sleep disorders.

"Sleep apnea not only causes fragmented sleep, but the intermittent pauses that sometimes happen as often as 30 times an hour," Archbold says. Such pauses "take a toll as well because the person is not receiving all the oxygen they need, and this can affect brain development, especially in children."

She says the number of cases of sleep apnea is on the rise in children and adults because more people are becoming obese, and sleep apnea is associated with those who are overweight.

Archbold says the most effective sleep apnea treatment is a CPAP, a device that delivers pressurized air through a flexible tube and special mask that helps open the airways during sleep.