Sleep is food for the brain. During sleep, important body functions and brain activity occur. Skipping sleep can be harmful — even deadly, particularly if you are behind the wheel. You can look bad, you may feel moody, and you perform poorly. Sleepiness can make it hard to get along with your family and friends and hurt your scores on school exams, on the court or on the field. Remember: A brain that is hungry for sleep will get it, even when you don’t expect it. For example, drowsiness and falling asleep at the wheel cause more than 100,000 car crashes every year. When you do not get enough sleep, you are more likely to have an accident, injury and/or illness. Continue Reading National Sleep Foundation.