The traditional wisdom states that you need eight hours of sleep per night, and for years that's been cited as the magic number. The truth is, though, that the need for sleep varies widely from person to person. In most adults, it ranges from five and a half hours per night to ten hours per night, depending largely, scientists now believe, on genetics. The only way to know for sure that you're getting enough sleep is to listen to what your body is telling you. 1. Do you have a hard time waking up in the morning? Some sleep experts go so far as to say that if you need an alarm clock to wake you every morning, you probably need to sleep more (or better) during the night. 2. Do you wake up feeling refreshed and ready for the day? If you regularly wake up still feeling tired, then you likely aren't sleeping long enough or well enough during the night. 3. Do you feel the need for a nap during the day, or find yourself falling asleep at odd times? If you regularly hit a wall midmorning or late afternoon, try adjusting your sleep schedule at night. 4. Do you fall asleep easily at night? Many experts say that if it takes more than five to ten minutes to fall asleep at night, then you may be sleep deprived. 5. Do you sleep longer on weekends than during the week? If you're getting enough sleep each night during the week, then you'll generally sleep the same number of hours on a weekend night. Your mattress can make a big difference in how well you sleep at night. For the best selection of mattresses to help you get a good night's sleep, visit www.mattressnextday.co.uk.