How Long Can You Survive Without Water?

After successfully distracting yourself by running your fingers on the hamster wheel that is your Instagram feed, you finally leave your devices alone to fall asleep. Instead, you find yourself in the uncomfortable unknown, where your inquisitive self bursts into life and vanquishes your sleep as you look closely and notice the unnoticed, ask the unasked, meandering just below your nose when you were consumed in the dailiness of your life. Wait a minute, Why do I have toe-nails?! Or I wonder how long could I survive without water?

Short Answer: On average, a person can survive 3 days without water, but some have reported to survive around 8 to 10 days.

Why is water so important?

Thirst is a survival instinct and I’m guessing by now you’ve realized that water is one of the most essential nutrients required by living things. Water regulates our body temperature, digestion, aids the disposal of waste and is needed by the brain to produce hormones and neurotransmitters. So… it’s pretty important. Clearly. 

Mind=Blown, right?

Water is the most abundant molecule in our body, making up more than 65% of our body’s liquid content. After using up the water from external sources, the body uses the water stored in our fat cells to satiate its thirst.

This is how camels survive without water for days in the scorching heat of deserts – by extracting water from fats all around their body. The human body, unfortunately, does not have as much storage capacity. After an excruciating week without water, sweating ceases, leading to an unavoidable increase in our body temperature and digestion becomes impossible due to a lack of saliva or intestinal juices, while blood pressure decreases due to low blood volume.

The water tide inside human body_

Under such feeble conditions, death is just around the corner. Surviving without water comes down to disrupting the balance between losing water and gaining it. This means that survival can be stretched if the rate of losing water through sweating, urinating or exhaling rapidly is less than the amount gained by consuming food and liquid.

How long can you live without water?

On average, a person can survive without water for about 3 days, but some have reported to survive around 8 to 10.

This amount of time can also be stretched and contracted by external factors, such as temperature, humidity and the health of an individual. For instance, athletes exercising intensely in the dry heat can dehydrate and die within hours. Whereas, the record holder for surviving the longest without water survived for 18 days after he was put in a jail and forgotten for over two weeks!

However, it is reasonable to point out that he was indoors in the absence of the sun or any heat.

Yep, forgotten.

Also, one can live without water indefinitely, provided you have eaten enough water-containing foods to replace the lost water. Our body doesn’t necessarily need “pure water”; it only requires electrolytes and nutrients in aqueous solution, so that they are available to be absorbed. It enacts a terminal step in a line of reactions involving the oxidation of hydrogen or hydrocarbons to provide energy.

Poon Lim, a Chinese sailor whose ship sank in 1942, survived 133 days on a raft in the open ocean. He ran out of supplies in the first month itself leaving him 3 months without a drop of fresh water! So how did he survive? He caught and ate fish and drank seagull or shark blood. However repulsive, it kept him alive.

So your query does not have a fixed answer. The average is about 3 days, but you could try out for yourself. Now, give your mind a break and get some sleep!


  1. The University of Chicago
  2. Georgia College
  3. The Pennsylvania State University
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About the Author:

Akash Peshin is an Electronic Engineer from the University of Mumbai, India and a science writer at ScienceABC. Enamored with science ever since discovering a picture book about Saturn at the age of 7, he believes that what fundamentally fuels this passion is his curiosity and appetite for wonder.

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