Your body constantly loses water throughout the day through urinating, sweating, and breathing.
You should consume enough water from foods and beverages daily to preventdehydration.
Generally, a person can only survive without water for a few days.

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When the body becomes too hot, it loses water throughsweat.
The evaporation of sweat from the skin cools the body, keeping its temperature within a normal range.
If a person becomes dehydrated, they can’t produce enough sweat to cool their body.
This can cause the body’s temperature to reach dangerous levels, leading toheat stroke.
Avoid dehydration by drinking plenty of water if you’re working outside or sweating more than usual.
It’s necessary to producesynovial fluid, which lubricates, cushions, and protects the joints.
Water also helps protect thespinal cordand prevents injuries by increasing tissue flexibility and elasticity.
Thekidneysneed water to effectively filter waste from the blood and flush it from the body as urine.
Staying adequately hydrated helps preventkidney stonesandurinary tract infections (UTIs), which can harm the kidneys.
It Aids Digestion
Your saliva is primarily made up of water.
Saliva also contains enzymes that help break down starches in food.
It Protects Against Chronic Illness and Boosts Longevity
Adequate hydration is linked to healthy aging and longevity.
Well-hydrated adults also seem to live longer than adults who don’t consume enough fluids.
Researchers found that 200 milliliters of water improved thirst, anger, fatigue, and overall mood.
However, 500 milliliters was optimal, improving mood and cognitive performance.
How Much Water Do You Need?
This includes fluids consumed from all foods and beverages.
Experts estimate that most people get around 20% of their daily water intake from food.
One easy way to see if you are properly hydrated is to check the color of your urine.
If you are drinking enough water, your urine will be pale yellow.
If it is dark, you may need to increase your consumption.
Individuals with heart failure or kidney disease may need to limit their fluid intake.
Can You Drink Too Much Water?
It is necessary for temperature regulation, digestion, nutrient absorption, and body waste removal.
Talk to a healthcare provider or registered dietitian to determine the right amount of water for you.
2022;9:822119. doi:10.3389/fnut.2022.822119
Academy of Nutrition and Dietetics.How much water do you need?
MaineDOT.The importance of hydration.
Johns Hopkins Medicine.Dehydration and heat stroke.
2019;11(8):1857. doi:10.3390/nu11081857
Centers for Disease Control and Prevention.Water and healthier drinks.
National Kidney Foundation.6 tips to be “water wise” for healthy kidneys.
National Institute of Diabetes and Digestive and Kidney Diseases.Your digestive system & how it works.
National Institute of Diabetes and Digestive and Kidney Diseases.Eating, diet, & nutrition for constipation.
National Heart, Lung, and Blood Institute.Good hydration linked to healthy aging.
2013;18(2):95-98. doi:10.6065/apem.2013.18.2.95
Centers for Disease Control and Prevention.Heat stress: hydration.