Many people take naps to try to catch up on sleep during the day when they don't get enough rest at night.
As aging occurs, sleeping problems can worsen.
Sleep apnea is a breathing disorder where the throat collapses or constricts during sleep. Breathing can stop for 10 to 30 seconds or more. That can dramatically lower a person's oxygen level.
Researchers from the University of California-San Francisco Sleep Disorders Center studied hundreds of women and found those who suffer from sleep apnea double their risk of cognitive problems.