Proper hydration is essential to your survival. Your body needs to consume a significant amount of water each day to function properly. This is because you constantly excrete water through sweat and urination, so your body needs to replenish the lost fluids.
You won’t live long without consuming a healthy amount of water. It’s only possible to survive without water for a matter of days. You may be susceptible to the effects of dehydration even sooner, depending on certain factors.
Dehydration is the medical term for not having enough water in your body to function properly. Your body needs a certain amount of water on a daily basis to maintain health. This is because water makes up 60 percent of your bodyweight. In children, water makes up to 75 percent of their bodyweight.
You can’t survive without water for very long, but the exact amount of time you can live without water varies. This is because certain factors contribute to your body’s use of water, including your:
- environmental conditions
- activity level
- food intake
These factors contribute to the way your body uses water. For example, in a hot climate, your body will sweat more, leading to more water consumption. Your body will be losing water more rapidly if you have a fever, are vomiting, or have diarrhea. You’ll also use more water if you’re exercising.
Additionally, some foods you eat will have more water in them than others. Water consumption also includes other beverages like herbal tea and juice. However, some beverages can contribute to dehydration, such as ones that contain caffeine or alcohol.
One study in Archiv Fur Kriminologie concluded that you can’t survive more than 8 to 21 days without food and water. People on their deathbed who are using very little energy may live only a few days or a few weeks without food and water.
Water is much more essential to your body than food. People who engage in hunger strikes without food but with access to water can live a few months or longer. One article in the British Medical Journal recommends that those engaging in a hunger strike drink 1.5 liters of water a day to maintain fluid levels in the body. The article also recommends adding a half teaspoon of salt to the water per day to replace sodium lost through sweating.
Because water intake is so critical to health, the Institute of Medicine of the National Academies recommends that women get 91 ounces of water per day and men get 125 ounces per day through both beverages and foods. This average recommended intake is for people who are healthy, not particularly active, and living in a moderate climate.
Your body is highly attuned to the amount of water you consume. You likely get enough water in your body based on your sensation of thirst. If you drink when you’re thirsty, you’re likely getting enough water in your body on a daily basis.
Without enough water, systems in your body will change. Your cells will shrink without enough water. Your brain will signal your body to urinate less. This will occur through your kidneys. They rely on an adequate water intake to function properly.
Without enough water, the kidneys use more energy and wear on tissue. Your kidneys need to function adequately to flush out waste from your blood. Eventually, your kidneys will cease to function without adequate water intake. Other organs in your body may also cease to function without water.
A lack of water will also impact other bodily functions. Without adequate water intake:
- Your body temperature won’t stay regulated.
- Your electrolytes will be unbalanced.
- Your joints may not work properly.
- Your brain may swell.
- Your blood pressure may increase or decrease.
You don’t just get hydration from water and other beverages alone. Food consumption contributes to 20 percent of your total water intake per day.
Some people may get even more water from their food if they eat a significant amount of fruits and vegetables, which contain a high amount of water. People in countries like Greece and South Korea include many more of these foods in their daily diets, resulting in more water intake through foods.
Fruits and vegetables with the highest amount of water include:
Other foods that contain a high amount of water include:
- cottage cheese
- chicken breast
Consuming foods high in water will help prevent dehydration. However, food alone isn’t likely to provide an adequate amount of water to sustain you in the long term.
Some of the side effects and risks of dehydration include:
- a lack of energy
- injury, like heat cramps or heatstroke
- brain swelling
- hypovolemic shock
- kidney or other organ failure
You must be careful with your fluid intake if you become dehydrated. The appropriate method of rehydration will vary from person to person.
Adults may just need to drink water to rehydrate. Small children may require a drink that includes sodium in addition to water to replenish the body appropriately. Children may need to take this solution in very small amounts at first.
If you’re severely dehydrated, intravenous administration of water and salt may be necessary.
Maintaining an adequate amount of water in your body is vitally important to your life. Without water, you’ll only be able to survive a matter of days.
Generally, your thirst will guide you when it comes to how much water you should drink. Keep in mind that exercise, hot temperatures, and illness can contribute to an increased intake of water to stay healthy. Contact your doctor if you suspect dehydration.