Is 6 hours of sleep enough?

For most adults good health requires a sleep duration of between 7 and 9 hours. Although six hours may be sufficient for a short period for some individuals, it usually leads to feelings of tiredness, poor concentration, and mood changes after a while. Since your body carries out its repairs during deep sleep, reducing the amount of sleep has a negative effect on both memory and immunity. If you consistently feel fresh and alert after only six hours, then it's possible that your body needs less sleep; but if not, you should try getting more sleep.