The modern world seems to have largely dismissed the importance of sleep despite having more evidence than ever for how important it is for human health. People see sleep as something to be avoided or as something that is irritating but not harmful to give up. Sleep, however, is as essential to survival as eating or breathing, and going without it will cause irreversible harm. Here are six facts about sleep deprivation that are frightening enough to keep someone up all night.

It is a form of torture.

Sleep deprivation is very literally categorized as a form of torture and is thus illegal. It also has a long history of being used to forcibly extract confessions for prisoners. Witch hunters in medieval times would “wake the witch” until the woman either told her interrogators whatever they wanted to hear regardless of its basis in truth or her extreme actions were taken as proof of her crimes. It was also used extensively in World War II, Soviet Gulags, apartheid South Africa and in the War on Terror. Confessions extracted through sleep deprivation are of questionable trustworthiness which is why so many women in medieval era agreed with their interrogators that they could curse people, but the practice does still continue today.

It causes psychosis.

Severe sleep deprivation is well known to cause psychosis. People subjected to extreme sleep deprivations, whether in deliberate malice or through circumstances such as a colicky baby or a sleeping disorder, begin to lose track of reality. Hallucinations are common as is a strong sense of paranoia and anxiety. People who are sleep deprived often end up hallucinating terrifying things. They may hear voices, see monstrous creatures, feel someone trying to attack them or have to face down other terrible creations of their own mind. These hallucinations can lead them to hurt themselves or others. Sleep deprivation induced psychosis also may make it difficult for people to get the sleep necessary to stop the hallucinations. No one, no matter how exhausted, would have an easy time getting to sleep when they are convinced a monster is in the room trying to kill them.

Sleep-deprivation induced psychosis is not limited to the unfortunate souls who have been deliberately kept awake for days on end. The chronic sleep deprivation caused by sleep disorders can lead to the same phenomenon as the person’s sleep debt builds up to unbearable levels. 

It is equivalent to being intoxicated.

Skipping sleep is actually equivalent to throwing back shots. Someone who is sleep deprived experiences the same inability to concentrate, lowered inhibitions, slowed reflexes and poor decision making skills that are found in those who are intoxicated. In fact, driving drowsy has been said to be just as dangerous in some cases as driving drunk. It is, however, far more common. Most people know better than to get behind the wheel of a car when they have been drinking. Few people, however, think twice about driving after a poor night of sleep. 

It causes a dangerous condition nicknamed “dirty brain.”

“Dirty brain” is a catch all medical term used to describe the state of a person’s brain when toxins, proteins and other byproducts of natural bodily functions and environment actions build up in the brain. This build up is associated with diseases such as Alzheimer’s. At best, the buildup interferes with normal neurological functioning. At worst, sections of the brain itself begin to die. 

The causes of certain dirty brain diseases are debated, but scientists do know that the body normally flushes those toxins from the brain when people are sleeping. When people skip out on their shut eye, the body cannot fully clean the brain. As such, the toxins and proteins begin to build up and can cause brain inflammation and dirty brain diseases.

It makes you psychopathic.

Sleep is essential to normal functioning. Without it, people effectively become psychopaths. When someone does not sleep, their sense of empathy is often one of the first things to really go. They might be overly emotional, but they likely struggle to really connect with anyone. To make matters worse, people who are short on sleep are also usually very short tempered and lacking in inhibitions. This combines to make them more likely to lash out at people and not feel guilty about it later. A lack of sleep also makes it harder for people to read the signals others are giving off. Someone who is sleep deprived is far more likely to make others uncomfortable or even feel unsafe. Not only can they not read the subtle signals the other person is giving them to back off, the sleep deprived person would not care about the other person’s feelings even if they could read those signals. 

It will kill you.

Sleep deprivation is quite literally lethal, and it can kill a person either directly or indirectly. Indirectly refers to the havoc that a lack of sleep causes the human body. Dirty brain diseases can lead to strokes or fatal degenerative brain diseases. Lack of sleep increases the risk of heart attack or embolisms. The inability to focus also greatly increases the risk of a person getting into an automobile accident. Sleep deprivation is also lethal in and of itself. Experiments carried out on animals show that a complete lack of sleep will eventually result in total organ shutdown and death. The same effect has been observed in humans who have fatal insomnia. This rare disorder can be either inherited, called fatal familial insomnia, or occur spontaneously, called sporadic fatal insomnia. In both cases, the victim of the disease slowly loses the ability to sleep. As they do so, their body suffers and their brain tissue begins to die. The disease, as is implied in the name, is terminal. There is no known treatment and suffers often die within months of developing the disease, though some have survived for a few years.

Sleep deprivation is not something to mess with, but too many people dismiss it as a minor concern. Left unchecked, it can and it will destroy a person. It is also very difficult to undo the damage a severe sleep debt can cause. Do not think that the horrors of sleep deprivation only affect other people. When it comes to survival, sleep is as necessary as food, and sleep deprivation will eventually extract the ultimate price. Nothing is worth that.