Deep sleep generally averages 2-4 hours for health benefits, depending on the individual. Deep sleep, also known as “golden sleep”, is a part of sleep that generally accounts for only about 25% of the total sleep time, averaging 2-4 hours under normal circumstances. If the deep sleep is less than 2 hours, but the next day is full of energy, no tiredness, is also normal. If deep sleep exceeds 4 hours and you still feel drowsy, it can also be considered as improper rest. The process of deep sleep is extremely important for brain health and promotes the body’s metabolism. Deep sleep and light sleep occur alternately and are not a continuous state. Minors need to sleep for a longer period of time and must ensure high quality in order to facilitate growth and development. Adults can adjust according to the needs of life and work in a timely manner, and try not to stay up late for a long time. Good sleep is good for health. Frequent insomnia needs to be examined by the neurology department of the hospital in time and treated actively.