What's a healthy amount of sleep? It differs from one country to another

Scientists Discover Genetic Mutation Linked to Needing Less Sleep

What’s a healthy amount of sleep? It differs from one country to another - EurekAlert!

Sleep is essential — researchers are trying to work out why. A typical person spends more than 20 years in a state of dreamy semi-consciousness. But surprisingly little is known about why we need this down time.