Sleep debt or sleep deprivation simply means you owe your body some sleep. It is the accumulation of not getting enough sleep. Sleep debt can cause mental and physical fatigue.
Scientists though are skeptical if sleep debt phenomenon does exist. Studies have shown though that consistent lack of sleep could cause daytime sleepiness.
In psychology, it is believed that if one owes sleep then he needs to sleep of half of the time owed. For instance, if the required amount of sleep each night is 8 hours and sleep only for 6 hours then you owe 2 hours but are only required to sleep 1 hour to pay the sleep debt.
Sleep deprivation is considered as one of the most pressing health problems in the United States. In 2002 a poll was conducted in America. Around 1,000 adults participated. One third of those polled said that they require 8 hours of sleep. They however sleep only for an average of 6.9 hours on weeknights and 7.5 hours on weekend nights.
A study using rats to determine the effects of lack of sleep to our body revealed that rats which were not able to sleep for around three weeks will die because of low body heat and infection.
In humans, similar total lack of sleep called fatal familial insomnia could lead to death after several months. The scientists though could not determine if the cause is sleep loss or brain damage.
Most often, lack of sleep for a night could cause a person to be irritable and tires easily. Lack of sleep for two nights could make the person lack focus and commit mistakes on routine tasks. Three nights of no sleep could cause hallucination.
A study in 1997 conducted on people who sleep only for four (4) or five (5) hours a day for one week revealed that these same people would require two full nights of sleep to be able to go back to their normal alertness levels.
