How Long Can You Survive Without Water?

Has any of y’all really been thirsty? Like ever? As I told you in the sandstorm survival story, I had an unfortunate bicycle ride through the Gobi Desert where I got pretty damn thirsty after my last bottle of water fell from my bike unnoticed. Still, I never felt like I was going to die.

At the first gas station, 30 miles onwards, I just gulped down a few pots of the free lukewarm green tea they served, and the problem was solved. Yet, the human body needs quite some water to function properly, and people have died in similar circumstances in a matter of hours. So how long can we really survive without liquid sustenance?

Rule of threes

Survivalists among us have all heard about the rule of threes: 

  1. You can survive three minutes without breathable air.
  2. You can survive three hours in a harsh environment (extreme heat or cold).
  3. You can survive three days without drinkable water.
  4. You can survive three weeks without food.

So, case closed, right? You can survive without water for three days. End of story.

Or maybe not?

What influences your ability to survive without water?

Whoever came up with the rule of threes must have realized it’s a massive generalization. Imagine adding any of the following variables into the equation:

  1. You’re not walking around in springtime Oregon, but in the Sahara Desert.
  2. You’re overweight and sweating profusely.
  3. You’re sick, with vomiting or diarrhea. 
  4. You’re two years old.

Got the idea? None of these people would survive without water for three days.

The human body can lose more than 3.2 pints (1.5 l) of water per hour under intense circumstances. Or even more, if you ask marathon legend Alberto Salazar, who did not only break American track records in 1982, but also holds the highest recorded sweat rate of 5.4 pints (3.06 l) per hour during an intensely hot Olympic Marathon. 

Without being able to replenish those vital liquids and salts, you will die within hours, as your blood volume drops, causing all kinds of trouble withing your body. This happens to people stranded at sea, people buried underneath rubble after an earthquake or to adventurers in the desert, as detailed in the desert survival story.

So how long can we really survive without water?

Scientists who observed people at the end of their lives, at a stage when they stop eating and drinking, saw that there were cases where people lived for up to seven days without water. Another research from Duke University claims that under average climatological circumstances, people can survive for 100 hours (4.5 days) without water. More if it’s cooler, and less if it’s hotter. 

However, the question remains whether you’ll survive if they dig you up after those 4.5 days. Like what happened to Buck Helm, a strong dockworker who got buried in his car after a viaduct collapsed during a 1989 California earthquake. He survived for 4 days without a drop of water, but a few weeks after he got pulled out, he succumbed to the internal damage the lack of water had caused.

So, the main question perhaps should be:

How long can I survive without water and still live a healthy life afterwards?

Aside from a wide range of variables that makes it hard to put meaningful numbers to this question, it’s a matter of how much internal damage gets done, despite your initial survival.

Because even if you manage to make it beyond those 3 or 4.5 days, there’s a strong chance your kidneys and other organs will have shut down irreversibly, and even with great medical care, your chances of survival might still be slim.

What happens when you don’t drink water?

  1. Blood starts to thicken and concentrate, so your heart has to pump much harder for the blood to circulate.
  2. You start having trouble swallowing, suffer from muscle spasms, and experience nausea. Your blood stops flowing to the skin and your body temperature increases. The lack of blood flow in your skin may cause you to turn a greyish blue colour. 
  3. Water goes from our cells into our bloodstream, and with dropping blood pressure, the chance of fainting increases. Your brain shrinks and your ability to take proper decisions goes down rapidly, another major cause of death. 
  4. After losing about 7% of body weight in fluids, your organs start to fail, meaning that the blood flow to the kidneys is slowed down to preserve the heart, lungs, and brain. From then on, the clock really starts ticking, and our question becomes extremely relevant. 
  5. With your kidneys barely functioning, waste quickly builds up in your blood stream. Also, the chance of a stroke increases significantly at this stage.

In extreme circumstances, these symptoms can happen in a matter of hours, leading to a swift and scary death. Unless you sit beside a pile of watermelons.

Can you survive on foods that contain water?

Obviously, you can survive on things that contain water. I won’t go too deeply into that. But think of watermelons and mangoes, or even milk and, as I wrote in the ocean survival story, turtle-, shark-, or seagull blood. 

What’s the longest someone survived without water?

This is a tricky one, as the record is slightly unclear. In 1979, 18-year old Andreas Mihavecz from Austria, was dumped into a holding cell by the police and then forgotten. After 18 days he was accidentally discovered by one of the guards, obviously close to death.

His survival is miraculous, though he allegedly licked condensation from the concrete prison walls, making it not a complete dry-fast.  

Can you survive for many days during a dry fast?

Speaking of which… For the good order, yet, without recommending it, I must mention Russian doctor Filonov’s dry fast retreats. During these retreats, he claims to take groups on a strict dry fast under medical supervision for up to 11 days!

Participants are not even allowed to brush their teeth or wash their bodies during that time.

People coming out of these dry fasts declare having rejuvenated skin and hair, weight loss (duh), higher energy, a drop in cravings for things like sugar and caffeine, and feeling positive effects on conditions like inflammatory arthritis. 

In a recently published book called Starving to Heal in Siberia, American author Michelle Slater shares her experience with Dr Filonov’s dry fast, as a last ditch resort to fight late stage lyme disease.

In it she claims to have completely fasted without water and food for up to nine days, and, through repeated dry fasts, managed to overcome years of struggle against this devastating disease. 

I’m not sure if this method has been properly studied, and how dangerous it can be, but in dry-fasting circles, Filonov’s retreats are highly praised. In any case, since all these retreats are supposedly done under medical supervision, it hardly counts as survival anyway, as you won’t have those fluffy circumstances when you get lost in the desert, in a mountain range or worse, at sea.

Still, as a disclaimer, I feel compelled to say: don’t try this at home. People have died while experimenting with dry fasting, or worse: breatharianism.

Could human beings survive entirely without water?

For those who take breatharianism seriously, be my guest. Some Indian yogis have claimed to live entirely on thin air, without eating or drinking anything. Few of them have been subjected to medical tests, but researchers refused to share detailed conclusions, and the self-proclaimed breatharians were allowed enough private time to stuff themselves if they had wanted to.

If being a complete breatharian is at all possible, disregarding obvious frauds like Wiley Brooks (read this hilarious interview),  who lost most of his followers after being spotted with biscuits and chicken pot pie at a 7-Eleven, these must be some superhuman yogi’s, which we are not.

So even if it’s somehow possible, it won’t help much to finally decide to take up meditation when you’re withering away in a desert hole without water. Although, you may as well. 


The best way to deal with thirst is to do your utmost to prevent it by preparing thoroughly, no matter where you go. Always keep spare drinking water in your car, make sure you have a communication device on you and that people know where you are. Then, when misfortune strikes, you will at least have done your part before starting the race against the clock. 

To be on the safe side, assume you cannot live longer than three days without water. In many survival scenarios, we won’t have ideal circumstances, so it will either be extremely hot, you may be sweating from exertion, or maybe you were slightly dehydrated before actually stranding already due to stress or other conditions.

When you’re on the spot, and in that desert hole, life raft or dry forest, know that panic is your worst enemy, and that if you conserve sweat, you may even be able to make it beyond science’s three days, thereby increasing the chances of being rescued. Because somehow, it appears that certain human bodies can survive without one of its most basic needs for longer than science says.

This post may contain affiliate links. If you make a purchase using links on our site, we may earn a commission at no extra cost to you.


More Articles