The healthiest amount of sleep for most people is between 7 to 9 hours of sleep per night to wake up feeling refreshed and energized as well.
But some people do require 12 hours of sleep at night to feel refreshed and wake up energized and be ready for the day.
Too much sleep though medically is considered more than 9 hours of sleep per night for most people and too much sleep can be bad for your health.
Getting too much sleep every once in awhile should not be harmful but getting too much sleep on a regular basis can increase the risk of diabetes, heart disease, stroke and early death.
Some people who have hypersomnia may require 10 to 12 hours of sleep to feel their best and sometimes it's okay while other times it's not.