People in the US sleep 1.5 hours less than they did a century ago

People in the United States sleep an average of 7.0 hours on weeknights and sometimes a little longer on the weekends. That's 1.5 hours less per night than we did a century ago. Although everyone's sleep needs vary, most healthy adults need an average of 8 hours of sleep a night. Difficulty waking up in the morning, waking unrefreshed, daytime sleepiness, irritability, difficulty concentrating and memory problems are signs you are probably not getting the sleep you need.