If you've ever travelled to a different time zone, you probably felt groggy and tired after your flight. Or you've likely missed that extra hour when the clock jumps forward for Daylight Savings time ...

Virtually every cell in the human body has an internal clock. These clocks take their cues from a central clock in the brain. In a normal, biological process called synchrony, the central clock ...

Did the holidays mess up your sleep patterns? Maybe you stayed up late ringing in the new year, or changed time zones while traveling. Science journalist Lynne Peeples says the body's circadian ...

The reason you’re energized to get out of bed in the morning, but tired enough to crawl back under the sheets again at the end of the day? Your natural 24-hour body clock, also known as your circadian ...