Did you know that you can dig yourself into sleep debt pretty much like you can dig yourself into financial debt? Every hour you put off going to sleep is like racking up another $100 on your credit card. Sleep debt is like a monetary debt--it must be paid back sooner or later. The size of the sleep debt you have is directly related to the amount of lost sleep. Everyone has a specific daily sleep requirement to feel their best. For most people, that's about 8 hours. Some people need less, some need more. However, research has indicated that most people are kidding themselves about how little sleep they need--it's the very rare person who needs less than 7 hours of sleep. Whatever your ideal amount is, that is the amount of sleep that must be obtained each day to avoid becoming sleep deprived. If the needed amount is not obtained, the lost sleep accumulates into a larger and large sleep debt.
All wakefulness is sleep deprivation! Some people think that the ordinary waking day is not sleep deprivation. They are wrong. Sleep debt can only be zero for a brief amount of time. Once sleep debt is zero, the sleeper awakens and begins accumulating sleep debt again. You must have a certain amount of sleep debt in order to fall asleep again. How much sleep debt you have also usually determines how quickly or slowly you fall asleep.