It is generally believed that adults need to have 8 hours of sleep a day. How many hours of sleep is enough for an individual? Doctors believe that the optimal amount of sleep is based on whether or not you can keep your energy up during the day. How can I tell if I am getting enough sleep? During the day, if you feel relaxed, energetic, do not feel sleepy and can focus on certain things, it means that your brain and body are well rested. Thus, the quality of sleep is not directly related to the length of sleep to a large extent. Although everyone should get the necessary amount of sleep, there is no need to be too demanding about the amount of sleep, and it may be more important to improve the quality of sleep and maintain a normal sleep mindset.