why is is still hard to fall asleep when you’re sleep deprived?


why is is still hard to fall asleep when you’re sleep deprived?

In: Biology

The same reason that made you sleep deprived in the first place… being nervous or whatever else.

Thoughts. Ever noticed how easy it is to fall asleep with a partner you love being next to? Or when all you care about is how comfortable your bed is after a long day? The consistent factor in falling asleep is focusing on your body’s sensations rather than your thoughts. Overthinking is, in my humble opinion, the leading cause of insomnia.

When you’ve used up all your regular energy your body produces adrenaline to help keep you going. It can turn into a vicious cycle. I struggled with insomnia as a teenager and ended up having heart palpitations from the amount of adrenaline my body was producing.


Having gotten stuck in a sleep deprived state for 3 days where my body just refused to shut down (no clue why I had no particular thoughts or concerns, no stress, nothing, just couldn’t fall asleep to save my life). At the end of the 3rd (approx 83 hours without sleep) day (day meaning 9ish pm) my roommate was freaking out about my inability to fall asleep (mostly because I was at a point where I could barely move, I wasn’t eating or drinking, and couldn’t form a coherent sentence. He ran to the store and got me melatonin and some sleeping pills, and I slept for 2 whole days without waking up at all.

It seems to me in hindsight that as I got more tired my body “forgot” how to shut down, and the longer it went the harder it became for me to get to that point. The worst part was that my mind was blank, no strong emotions or thoughts, no reason to be stressed or nervous. It was literally the calmest 3 days of my life (I have anxiety issues), I’m pretty sure I could feel death’s icy hand on my shoulder right as I fell asleep, and the only reason I woke up on the 2nd day was due to hunger since I hadn’t eaten in 4 days…

When you are sleep deprived, your body produces more cortisol (stress hormone), which among many things, keeps you awake. It is one of our evolutionary adaptations in which when danger is present (or in modern day, stressors), our body is able to somehow keep going despite decreased sleep.

In the simplest way, it’s a natural response by being sleep deprived your body is tricked into thinking there MUST be a really good survival-related reason for it. Think caveman times, maybe. Something is going to try to eat you or a tribe member and you HAVE to be awake to protect yourself or run.

More like a ELIJGHS (explain like I just graduated high school):

Your body uses two mechanism to control how tired you are and when you go to sleep. Your sympathetic nervous system turns your body up and gets you energy to do things. Your parasympathetic nervous system turns your body down and gets your organs ready to rest and recover.

When you do things your body depletes sugar stores. These stores need to be replenished. Also when you do things your body produces waste. This waste builds up and needs to be removed. Usually when your sugar stores are low and your waste products are high, your parasympathetic nervous system kicks in, you feel sleepy and you go to sleep.

But, sometimes you still need to do things. Maybe you need to cram for a big test the next day. Maybe you have a big interview you need to prep for. Well to keep you up, your body will turn up your sympathetic nervous system. This does not magically replenish your sugar stores, nor does it get rid of the waste products.

The uncomfortable feeling you get is your body attempting to release enough sugar from sugar stores that are already empty. It’s your body trying to get rid of waste products when the waste collection facility is already taxed.

For some people though, the powering through isn’t a forced condition its automatic. Instead their sympathetic nervous system has a faulty read code. So when these people lie down for sleep at night, their sympathetic nervous system kicks in. This causes the sugar stores to be released into the blood, it causes dilation of the bronchus and bronchioles, and the list goes on. Now the body is no longer ready for sleep but instead is ready to power through its tiredness.

For other people their parasympathetic nervous system just doesn’t come on hard enough. Their body is taxed for the day. They are ready to call it quits. But the signal doesn’t come hard enough from the parasympathetic nervous system. So they lay in bed waiting for the rest to come but it just doesn’t. The body lingers in a half state of rest.

For the first type of person, they need Beta Blockers to keep their body from interpreting the sympathetic nervous system.

The second type of person needs a drug to stimulate the parasympathetic system.

In both cases the most effective course of treatment is to incorporate an aggressive exercise regimen.

You know what my secret is? Whatever I want to do, I try the opposite. If I can’t sleep, I try to stay awake and watch a video or listen to a podcast. Out like a light. When I know I need to sleep because something is important, I wont be able shut my eyes with scotch tape.

sleep deprivation causes stress, stress hormones keep you awake.

stupid bot thinks short answers are bad

stupid bot thinks short answers are bad

stupid bot thinks short answers are bad

stupid bot thinks short answers are bad

On a side note, if I ever encounter severe insomnia, I usually try to stay awake thought the whole day and not touch my bed until it’s bedtime, I almost always fall asleep after imbibing a beer, since alcohol makes me drowsy and calms me down a lot. Maybe it counteracts the adrenaline/cortisol.

I guess this isn’t something I should reccomend, but it has worked for me.

To keep this as simple as possible for an ELI5, there are a number of things going on in your body that determine when you feel tired and when you actually fall asleep.

The two most important factors are your circadian rythym and sleep-wake homeostasis which are supposed to work in harmony to control your sleep cycle.

Circadian rythym is like a 24 hour internal clock controlled by your hypothalamus that affects a number of biological functions like your metabolism and hormone release, but most importantly when you feel alert and sleepy throughout the day.

Sleep-wake homeostasis is basically an internal measure of how much you need to sleep. This just continues to go up and up the longer you are awake.

It gets fairly complicated but both of these factors work together with a number of different areas of your brain when you are getting ready to sleep, making sure certain functions of your body stay active while others are switched off, e.g. the pons and medula signal muscles in your body to relax so that when you enter REM sleep and your thalamus is sending out visual and audio signals etc, you don’t start physically running in your bed because you are dreaming you are being chased down the street.

The problem is that because this process is so involved, so many different things can disrupt it, either by causing your circadian rythym and sleep-wake homeostasis to become out of-sync or getting in the way of the biological functions that allow the brain to work in the way we discussed to send you to sleep (release of chemicals melatonin and GABA etc).

Things like exposure to light, medicines or other chemicals you have ingested, medical conditions, the environment you’re trying to sleep in, your diet, how much physical activity you’ve done and stress can all greatly disrupt these functions. So ironically, if you’re super sleep deprived and feeling really tired, you might get anxious about whether you’re going to get enough sleep, especially if you have a big/important day coming up. That anxiety and worry could disrupt your ability to sleep even while you lie there feeling more exhausted than you’ve been all year.

It is related to the functions discussed above but there are also electrical patterns of brain activity that play a role in this. This starts to get quite complicated again and I’m already explaining it badly so I’ll just give a quick example. The reason why many people find it easy to fall asleep watching tv is because watching tv often only stimulates a very specific and small part of your brain. As the rest of the brain isn’t being actively used for anything, the electrical activity throughout the brain starts to die down, triggering the functions that get you ready for/send you to sleep. In the end the overwhelming desire of the rest of the brain to sleep also shuts down the part of your brain being stimulated by watching tv.

TLDR; the human body in general, and specifically sleep function, is very complicated and it is hard to give a short answer about what makes us sleepy and how we actually physically get to sleep. The best thing you can do is research the factors that are proven to affect sleep (exposure to light, sleep environment, stress, diet, level of physical activity, etc) and try to control them to the best of your ability. In the end, if you consistently struggle with sleep issues see a doctor as getting sufficient sleep is one of the most utterly important factors in good physical and mental health. The benefits of sleep have been demonstrated over and over and there are also many demonstrated serious negative effects from lack of sleep.

On that note, good night and sweet dreams!

My doctor told me that sleeping actually takes energy. You won’t be able to sleep as good if your body doesn’t have the energy to do so.