Does short sleeper syndrome really exist - people can achieve the same level of rest as a conventional sleeper but in a shorter period of time   Live Science - January 17, 2023

Short sleeper syndrome (SSS) is a sleep condition characterized by sleeping for fewer than six hours each night. Most adults need seven or more hours of sleep each night to feel rested in the morning. Those with SSS, however, can function normally throughout the day despite less sleep. They don't need to take naps or sleep more than normal to recover from lack of sleep. These individuals are different from those short sleepers who choose to limit their sleep.

For humans, a nightly doze plays an important role in health: It enables people to think clearly, function effectively and provides an opportunity for the brain to wash itself. Most adults require between seven and nine hours of sleep per night, according to the National Sleep Foundation (opens in new tab), yet some people have as little as five or six. Former U.S. president Barack Obama, for example, admitted to sleeping for as few as five hours per night during his presidency, while Margaret Thatcher, the former prime minister of the United Kingdom, claimed she only needed to get her head down for four hours each night.