Just about everyone can name someone who snores like a chainsaw -- but a cloud of mystery and denial still swirls around the condition often confused for regular old snoring, sleep apnea.
Sleep apnea is marked by pauses in breathing -- up to hundreds a night -- that leave the affected person excessively tired during the day. But, at least partially because it's most common in older men or people who are overweight, sleep apnea is often shrugged off by snorers who think it couldn't happen to them.
While it's difficult to pinpoint the exact number of people with sleep apnea, the National Sleep Foundation estimates it's around 18 million -- or higher, significantly more than some health conditions that receive much more attention, say sleep experts. The chart below helps put those numbers into perspective.