Why You Can’t Sleep Longer Than 4 Hours – & How to Fix It

It’s the middle of the night.

You did your whole night-time routine. You felt relaxed, rested. Teeth were brushed. Bedroom is tidy. Screens were off.

Yet here we are. 3am again. 4 hours in and suddenly your brain is wide awake. Let’s start thinking about every little aspect of our lives, it says.

Being stuck in a cycle of waking up after 4 hours of sleep isn’t uncommon. It can happen to many of us.

Like with anything sleep-related, though, there’s never just one cause. Disturbed sleep can come from a variety of different reasons. To help, I’ve put together most common things that might be keeping you to such a short sleep period.

While I’m not a doctor, I can present known issues case by case. These might give you some ideas about things you can change, or reasons why you might be stuck at a maximum of 4 hours of shut-eye.

Bad Sleep Hygiene

Don’t worry, I’m not accusing you of SWS (sleeping while stinky).

‘Sleep Hygiene’ is how sleep scientists refer to your sleeping habits. These are the ways we setup ourselves up for sleep – helpful or otherwise.

Typical ‘bad sleep hygiene’ includes habits like:

  • Too much caffeine
  • Screens before sleeping
  • Bad environment (noisy, bright, hot)
  • Uncomfortable beds or mattresses

Thankfully, sleep hygiene’s usually pretty easy to fix. Like a hot shower after a muddy day out, cleaning up bad habits can be enjoyable and leave us with a sense of comfort and calmness.

Below are a few ways your sleep quality might be suffering. While each can be a small change, they quickly stack up to helping ensure you easily get past sleeping beyond the 4 hour mark.

Bad Sleeping Environment

Creating the ideal sleeping environment is super simple. You just need to focus on 3 things:

  1. Darkness
  2. Quietness
  3. Coolness

The three of these, combined, are the secret to getting amazing sleep. Especially in encouraging sleep to last longer than just 4 hours.


This is the easiest one to solve. No matter where you are, a simple sleeping mask will solve this even in the worst of cases. However, investing in black-out blinds or heavy curtains can also give huge returns.


Keeping things quiet can get a little tricky. Believe me – I used to need to sleep early in an apartment where I could hear: church bells clanging, banging cooking equipment in the kitchen, screaming kids next door, police sirens, and people on the street!

If there’s a lot of external noise, the best solution is a good set of ear plugs.

Massive stress on the word good, here.

Good ear plugs are made of wax or silicone, and mould to fit right inside your ear.

Bad ear plugs are the crappy foam ones which cost a buck fifty from Walmart.

There’s a HUGE difference here, trust me. See the recommended gear page for, well, recommendations.


This is the hardest one to fight. If you don’t have air conditioning, it’s difficult to turn down the temperature of the entire world.

That being said, there are things we can do. Check out some of our best tips in this article on sleeping without air conditioning.

You Have The Short Sleep Gene

Sometimes it seems like half the human race has the “short sleep gene”.

From your business-loving uncle and ambitious friends, to presidents and CEO’s, it seems like everyone says they can “get by” on less than 6 hours of sleep.

Unfortunately, that’s just not true.

Fact: A gene does exist which lets lucky people function fine on 4-6 hours of sleep.

Also Fact: You have more chance to be struck by lightning that to have this gene. It’s ultra rare!

The chances are, most people who think they are healthy while running on little sleep are incredibly impaired. So impaired, for so long, that they don’t realize how sleep deprived they’ve really become.

If you think you might have the gene, here’s a quick test. Think about these questions:

  • Are you filled with energy, all day long?
  • Do you naturally wake up after 6 hours or less sleep?
  • Are you feeling refreshed and raring to go upon waking up?
  • Does the idea of using coffee/caffeine to stay alert seem ridiculous?
  • Do all of these stay true during weekends and on vacation?

Only if you answered a quick “yes!” to all of these would I say you might have the gene. For the rest of us, such a low amount of sleep will simply leave us impaired. Running on fumes as lesser versions of our best selves.


This is the big one. The underlying condition that loves to rear it’s head in the worst of ways. It’s favorite is to mess with our sleep.

If you’re going through a challenging time in your life, the stress can quickly disturb your ability to sleep. Even if it doesn’t feel like you’re stressed. If there’s a lot going on, especially personally, it may be overflowing into your sleep schedule.

While I categorize many things under stress, this includes issues like depression, anxiety, and grief.

If you’re going through an especially challenging time, try to talk to a professional about it where possible. Always try to share with friends or family you trust, too. A problem shared is a problem halved.

In terms of habits, incorporating things like meditation, regular exercise, daily exposure to sunlight, and time to be calm (reading, reflecting, taking a bath) can help soothe your mind.

Drug Dependency

Now, I’m not saying you’re reading this after taking your list hit of an opiate.

The two main drugs that cause sleeping issues are actually caffeine and nicotine.

While one prevents the onset of sleep, the other can massively shorten sleeping lengths.


Let’s start with the obvious.

Caffeine keeps us awake. It temporarily removes the hormone which causes sleep pressure (Adenosine) while causing us to feel more ‘buzzed’. Great for productivity, bad for feeling sleepy.

Caffeine has a half-life of 6 hours. That means if you have a cup at 3pm, 50% of it is still active at 9pm. Not ideal!

Try to limit caffeine intake where possible. Ideally, put a 2pm cut-off on cups of coffee.

Be aware that caffeine is also found in sodas and teas. Many people wire themselves into sleeplessness without even noticing.


Now with the not so obvious.

Scientists have found that nicotine addicts (aka smokers) have such a powerful need for the substance that their bodies will pull them out of sleep for it.

It’s almost the same as a drug addict spending their last dollars on the next hit, and not a good meal.

Smoking or vaping too much can cause your body to need a ‘hit’ so bad that it wakes you up. This is part of a vicious cycle. By having disturbed sleep, you get tired and lose willpower. Which makes you smoke more. Which disturbs your sleep…

What Happens When You Only Get 4 Hours of Sleep?

Here comes the hard part. Running on half the amount of sleep gives us WAY more than double the problems. “Sleep debt” builds up day by day. The longer you spend stuck on 4 hours of sleep, the worse your tiredness symptoms get.


You’re unable to focus. Concentration is one of the first things to go when we’re tired. This isn’t just when reading helpful sleeping blogs – it’s doing things like driving, too.

Here’s data from the AAA Foundation for Traffic Safety. They looked at how tired drivers were after crashes; how much sleep they had the night before. It’s shocking how drastically the risks increase.

Risk of Car Crashes vs Hours of Sleep
The longer you’re awake, the greater the loss in concentration.

Forgetting things easily. Sleep is when we forge and reinforce memories. The longer you stay awake, the quicker you’ll forget things in your short term memory, or fail to move them into your long term memory for learning.

You lose your willpower. Willpower is like a battery. After a good rest, you wake up with a full charge. Which you use throughout the day – and eventually it runs out. Suddenly resisting those fries become impossible. On low sleep, we only start the day with half a charge (or worse).

You get moodswings. Have you ever noticed that the worst fights with couples are always when we’re tired? Tiredness makes us way more irritable and prone to swinging to extremely giddy or grumpy. Our brain can’t properly control our emotions.

And, unfortunately, much more. For a full (and more detailed) list of what tiredness causes – check out our post on the effects of 6 hours of sleep here.

To Wrap Up

Being stuck only being able to sleep for 4 hours can be a real nightmare.

Almost so much that you wish you were having nightmares – because you’d at least be asleep!

I hope that this guide has given you a few ideas of changes you can make. They may seem small, but a few changes can be the difference between a full night’s sleep or a middle-night rise.

If this content’s helped you, please consider checking out some of the related posts below.

Thanks for reading! Sleep well.


Helping you get the best night of sleep possible. Sharing what I learn through my research and testing.

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