Water is essential for human life. Every cell, tissue, and organ in the body requires water to function properly. So how long can someone survive without any water intake? The simple answer is: not very long. Humans can only survive a few days without water, depending on temperature and activity level. However, there are some extraordinary cases of people surviving weeks or even months with no water. In this article, we’ll take a deeper look at water requirements, how long humans can realistically survive without it, and some extreme examples of water deprivation survival.
How Much Water Does The Human Body Need?
The amount of water a person needs varies based on age, health, activity level, and climate. Here are some general daily water intake recommendations:
- Adult men: 15.5 cups (3.7 liters)
- Adult women: 11.5 cups (2.7 liters)
- Pregnant/breastfeeding women: 13 cups (3 liters)
- Children ages 1-3: 4 cups (0.95 liters)
- Children ages 4-8: 5 cups (1.2 liters)
- Older children and teens: 8-10 cups (1.9-2.4 liters)
About 20% of our water intake comes from food, while the remaining 80% comes from drinking water and beverages. Factors like sweating, urination, breathing, and bowel movements cause us to lose water throughout the day, so we need to continually replenish it.
How Long Can Humans Survive Without Water?
On average, humans can only survive:
- 3 days without water
- 21 days without food
Going without water will be fatal before malnutrition sets in. However, survival times can range from as little as 3 days to as much as 10 days, depending on variables.
Variables That Affect Survival Time
- Temperature: Hot temperatures lead to increased sweating and more rapid dehydration.
- Humidity: Dry air dehydrates the body faster than humid air.
- Activity level: The more active a person is, the more water their body requires.
- Body size & composition: People with more body fat or more overall mass can survive longer.
- Circumstances: Trapped miners or shipwreck survivors have survived longer without water due to resting and lower temperatures.
- Health conditions: Illnesses like diabetes can shorten survival time.
- Mental state: Determination and calming the mind can slightly extend survival.
As you can see, there are many variables affecting how long a person can realistically go without water. Next, we’ll look at what happens inside the body when deprived of water.
Stages of Dehydration and Effects on The Body
The effects of dehydration worsen over time and happen in stages as the body copes with less and less water. Here are the general stages of dehydration and their effects:
1% Dehydration
- Thirst and general discomfort
- Slightly dry mouth, eyes, and skin
- Decreased urine output
5% Dehydration
- Fatigue sets in
- Increased heart rate
- Dry mouth, eyes, skin, and lips
- Skin may lose elasticity and not “bounce back” when pinched into a fold
10% Dehydration
- Muscle cramps and spasms
- Nausea and vomiting
- Trench-like coating on tongue and dry swallow
- Little or no urine; concentrated urine color
- Headache, dizziness, and fainting
15% Dehydration
- Numbness in limbs
- Low blood pressure
- Fever with or without sweating
- Extreme thirst with shriveled tongue
- Decreased consciousness, delirium, seizures
Beyond 15% dehydration is extreme danger of circulation collapse and kidney failure. Death generally occurs above 20% dehydration without treatment. As you can see, the effects compound the longer someone goes without water. Next we’ll look at some unique cases where people survived for weeks or months without water.
Extreme Survival Without Water
While very rare, there are some well-documented extreme survival stories of people lasting weeks or months without fluids. Here are a few of the most remarkable cases:
Andreas Mihavecz – 18 days without water
In 1979, an 18-year-old Austrian man named Andreas Mihavecz fell into a coma for 18 days due to a head injury. During that time, he received zero water. He survived off his own fat stores and the water his body’s cells retained. When he awoke from the coma, doctors were amazed by his recovery.
Rhonda Cornum – 8 days without water
Rhonda Cornum was an Army flight surgeon whose helicopter got shot down during the Gulf War in 1991. She suffered two broken arms, a shattered knee, and other injuries. During 8 days as a POW, she was provided no water or liquids. She recovered fully, crediting her survival mindset and healthy body composition.
Erika & Helmut Fritzl – 7 days without water
In 2008, Josef Fritzl was arrested in Austria after keeping his daughter Elisabeth trapped in a cellar for 24 years. In that cellar dungeon, two of the seven children he fathered with Elisabeth were born. At times, Fritzl let his prisoners go without food or water for over a week. The longest was a 7 day stretch with no water at all. The two children born in the cellar, aged 5 and 12 at the time, somehow survived this extreme deprivation along with their mother.
Key Factors in Water Deprivation Survival
Analyzing the accounts above and other extreme survival stories reveals some common factors that enable humans to live far longer than a week with no water intake:
- Lower temperature environments – minimizes water loss through sweat.
- Lower physical activity – the less active the body is, the less water it requires.
- Increased body fat – provides stored energy and liquids.
- Mindset – Determination to survive at all costs.
- Young age – children seem to handle water scarcity better than adults.
- Tolerance – the body can adjust its osmolarity and gradually tolerate more dehydration.
While these factors have enabled some people to survive 2-3 weeks without water, such deprivation still causes major health complications. Next we’ll look at the kinds of damage and renal failure that can result.
Health Consequences of Prolonged Dehydration
If someone is deprived of water for many days or weeks, they may survive past 10 days, but not without consequences. Here are some of the damages prolonged dehydration causes:
- Electrolyte imbalances
- Sodium retention
- Hypernatremia (too much sodium in blood)
- Uremia and kidney failure
- Seizures and coma
- Tachycardia (elevated heart rate)
- Hypotension (low blood pressure)
- Anemia (low red blood cell count)
- Poor blood circulation
- Muscle and nerve damage
The kidneys suffer most from extreme water deprivation. Renal failure occurs when they can no longer filter fluids and waste from the bloodstream. If the kidneys and circulation shut down past a certain point, toxins build up and the condition becomes fatal. Death from prolonged dehydration usually involves multiple organ failure.
Kidney Damage and Renal Failure
After 10-14 days without water, cells in the kidneys begin dying and the organs shrink in size. Without emergency rehydration, kidney failure is imminent. However, even with treatment, severe and permanent renal damage may already be done. Kidney function may not fully recover if the organs have shrunk too much.
Let’s now examine the timeline of how kidney failure advances due to dehydration.
Progression of Dehydration Kidney Failure
| Time Without Water | Effects on Kidneys |
|---|---|
| 1-3 Days | Concentrated urine, decreased output |
| 4-7 Days | Greatly reduced urine, renal blood flow decreased 60% |
| 7-10 Days | Oliguria – very minimal urine produced |
| 10-14 Days | Anuria – complete failure to produce urine, ischemic damage to kidney tissues |
| 2+ Weeks | Permanent kidney shrinkage and failure if not treated |
So while very rare cases may survive 2-3 weeks without water, kidney function is generally irreversibly damaged in the process without medical treatment. Next, let’s examine how the body can rebalance itself after water deprivation.
Rehydration After Water Deprivation
In rare cases where someone survives beyond 10 days without water, they face dire health consequences unless they can be immediately rehydrated. However, this rehydration process must be done carefully and gradually in medical facilities.
Dangers of Rapid Rehydration
After losing 15-20% of their water weight, abruptly rehydrating by drinking a lot of fluids can shock the system and be fatal. This causes:
- Sudden drop in serum sodium (hyponatremia)
- Imbalanced electrolytes
- Cerebral edema (fluid buildup in brain)
- Congestive heart failure
So oral rehydration has to be done slowly, even if the person is extremely thirsty after 10+ days dry. IV fluids also need to be administered gradually to prevent overload and shifts in osmolarity. Doctors balance IV sodium levels using diluted saline to stabilize the parched body. Next, we’ll look at the gradual process of successful rehydration.
Gradual Rehydration Process
| Phase | Treatment Protocol |
|---|---|
| Initial | Slow oral rehydration with diluted fluids or small sips of water |
| Secondary | IV fluids to gradually restore circulatory volume without overwhelming kidneys |
| Maintenance | Monitor fluid balance and electrolyte levels until stabilized |
A patient rescued from extreme dehydration may need to remain in the ICU for days or weeks while their kidneys, circulation, and systems slowly recover. They will likely have lasting renal impairment if deprived of water for 2 weeks or longer.
Conclusion
In conclusion, human survival without water is limited to a matter of days, on average. But in rare circumstances, some people have endured 1-2 weeks without fluids. This depends greatly on physical factors like temperature, physique, health status, and mental determination. However, even surviving past 10 days without water results in kidney damage and other complications. The body can gradually rebalance itself with cautious rehydration, but permanent organ impairment may occur. Still, the incredible human drive to survive can occasionally prevail, keeping someone alive for weeks without water under the right conditions.