Why We Need Sleep

Many teenagers think that sleep is a waste of time, especially during exams or on a weekend with friends. However, scientists have shown that sleep is just as important as food and exercise. While we sleep, our brains are busy. They sort the information we have learned during the day and store the important parts in our long-term memory. That is why students who sleep well after studying often remember more than those who stay up all night. Sleep also helps the body. During deep sleep, the body repairs muscles and strengthens the immune system, which fights illness. How much sleep do we need? It depends on age. Primary-school children need about nine to twelve hours, teenagers need eight to ten, and most adults need seven to nine. Many teenagers actually get less than they need, partly because their body clocks change at that age, so they feel awake later in the evening. There are simple ways to sleep better. Go to bed at the same time every night, and switch off screens an hour before bed, because the bright light can make it harder to fall asleep. If your room is quiet, dark and cool, you will probably drift off more easily.