Editor’s note: This is part of a series called “The Day Tomorrow Began,” which explores the history of breakthroughs at ... water or air to our survival. Typically, sleep is defined as an altered ...

During sleep, the body undergoes critical repair processes that help fight illness, heal wounds, and recover from the stresses of day-to-day life. Adequate amounts of restful sleep have been ...

Study reveals that sleep traits predict over 15% of body characteristics across 15 physiological systems, with visceral fat, ...

Even though we spend about one-third of our lives sleeping, probing how sleep works seemed a trivial, soft science to most researchers in the early 20th century. But the nightly habit intrigued ...

While experts don't yet fully understand sleep's effects on the body, it is clear that getting inadequate sleep can do more than just make you feel tired during the day. Over time, it can be a ...