That’s pretty incredible, given that the average person sleeps ... families with shortened sleep cycles. Again, mice engineered with those mutations slept less, with no obvious health consequences.

While caffeine tolerance can vary from person to person ... take the edge off the panic of not getting enough sleep, remember, there are no perfect sleepers, says Khosla. "It's normal to wake ...

In 1893, psychologist Mary Calkins led a sleep study by candlelight ... there is still no definitive biomarker signaling that a person is dreaming. Over the past decade, increased attention ...

Obstructive sleep apnea is when a person stops breathing five or more times ... those who had fewer than five sleep disruptions per hour, or no sleep problems; those with five to 15 disruptions ...