How Much Water Is In The Human Body

logo by Editorial Staff | Updated on July 30th, 2022

Water is necessary for all life on, within, and above the Earth. This is significant since you are largely formed of water. Learn about the benefits of water to the human body.


The Water in You: The Human Body and Water

Water performs a variety of critical activities to keep us all alive.

Consider what you require to survive, and survive. Food? Water? Air? Facebook?

Naturally, I’m going to focus on water in this case. Water is essential to all living things; in certain creatures, water accounts for up to 90% of their body weight. Water makes up to 60% of the adult human body.

According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart comprise 73% water, while the lungs are around 83% water. The epidermis is 64% water, the muscles and kidneys are 79% water, and even the bones are 31% water.

Humans must swallow a specific quantity of water each day to survive. Of course, this varies depending on age and gender, as well as where one lives. An adult male requires around 3 liters (3.2 quarts) of water per day, whereas an adult female requires approximately 2.2 liters (2.3 quarts) per day.

All the water a person need does not have to come from drinking liquids, as some of it is found in our food.

Water performs a variety of critical activities to keep us all alive.

  • A necessary nutrient for the life of every cell, it first serves as a construction substance.
  • It controls our body temperature through sweating and respiration.
  • Water in the bloodstream metabolizes and transports the carbohydrates and proteins our bodies utilize as food; it aids in expelling waste mostly through urine; it works as a shock absorber for the brain, spinal cord, and fetus; and it makes saliva, which lubricates joints.

According to Dr. Jeffrey Utz, Neuroscience, Pediatrics, Allegheny University, various people have different percentages of their bodies made up of water.

  • Babies have the most, accounting for around 78 percent of all births. By one year, that percentage has dropped to around 65 percent. Water makes up over 60% of an adult man’s body.
  • However, fat tissue contains less water than lean tissue.
  • Adult women have more fat in their bodies than males. Thus, roughly55 percent of their bodies are made up of water.

Thus:

  • Babies and children have more water (as a proportion of their body weight) than adults.
  • Women use less water than males (as a percentage).
  • People with more fatty tissue have less water than those with less fatty tissue (as a percentage).

The tables below show the average percentages and ranges of water in the body based on gender and age:

Age 12–18 yearsAge 19–50 yearsAge 51 years and older
MaleAverage: 59%
Range: 52–66%
Average: 59%
Range: 43–73%
Average: 56%
Range: 47–67%
FemaleAverage: 56%
Range: 49–63%
Average: 50%
Range: 41–60%
Average: 47%
Range: 39–57%
Birth to 6 months6 months to 1 year1–12 years
Infants and childrenAverage: 74%
Range: 64–84%
Average: 60%
Range: 57–64%
Average: 60%
Range: 49–75%

Where does water exist in the body?

Water may be found everywhere over the body. Cells hold 60% of all water in the body, with the remaining one-third around the cells.

Some organs contain far more water than others. The brain and kidneys have the largest amount of water, whereas bones and teeth have the lowest.

The figure below shows the percentages of water ranging from the highest to the lowest:

Body partWater percentage
Brain80–85%
Kidneys80–85%
Heart75–80%
Lungs75–80%
Muscles70–75%
Liver70–75%
Skin70–75%
Blood50%
Bones20–25%
Teeth8–10%

Without an abundant liquid water supply on Earth, there would be no you, me, or your dog. Water’s distinct traits and properties make it essential and fundamental to life.

Our bodies’ cells are filled with water. Water’s exceptional capacity to dissolve many substances enables our cells to utilize important nutrients, minerals, and molecules in biological processes.

The “stickiness” of water (due to surface tension) influences our body’s capacity to transfer these elements throughout our bodies. Water in circulation metabolizes and transports the carbs and proteins our bodies utilize for nourishment. Water’s capacity to move waste material out of our bodies is equally crucial.

What Role Does Water Play in the Body?

Water has several functions:

  • Water is the fundamental building block of cells.
  • It functions as an insulator, keeping the internal body temperature stable. This is partly due to water’s high specific heat and the body’s use of sweat and respiration to controlling temperature.
  • Water is required for the metabolization of proteins and carbohydrates utilized in meals. It is the main component of saliva and is needed to break down carbs and help in the swallowing process.
  • The substance lubricates joints.
  • The brain, spinal cord, organs, and fetus are all insulated by water. It is a shock absorber.
  • Urine is used to removing waste and poisons from the body.
  • Water is the body’s primary solvent. Minerals, soluble vitamins, and some nutrients are dissolved.
  • Water transports oxygen and nutrients into cells.

How to Keep a Healthy Percentage

It is critical to consume adequate water to sustain all bodily processes. Most people obtain adequate fluids during the day via meals and beverages. In warmer weather or after activity, they should consume extra water.

In addition, the Centers for Disease Control and Prevention (CDC) recommends:

  • bringing a water bottle with you for quick access
  • choose water over sugar-sweetened drinks
  • When eating out, choose water and add a wedge of lemon or lime to it to boost the flavor.

Some suggestions for older individuals include:

  • not delaying drinking fluids until thirsty
  • taking a sip of water between each piece of food during meals drinking a glass of water before and after exercise
  • When taking medicine, drink a full glass of water.

There is no predetermined amount of fluid that a person should drink daily. The quantity varies according to a person’s age, gender, weight, health, physical activity, and the environment in which they reside.

How do you know if you’re dehydrated?

Dehydration’s external signs and consequences are visible, ranging from dry skin and lack of energy to brain fog and muscular cramps if you exercise without appropriately replacing the water you lose via sweat.

On the other hand, the consequences of chronic dehydration stretch down into the cells, which, like the organs, require adequate water to operate properly and eliminate metabolic waste from the body.

The following are some of the most prevalent signs and symptoms of dehydration:

  • Dark urine
  • Thirsty
  • Breath problems
  • Muscle cramping and exhaustion
  • Headaches
  • Skin that is parched
  • Their blood pressure is low.
  • If you’re exercising and should be sweating, you may have decreased sweat production or clammy skin.
  • Cravings for sweet, sugary foods have increased (one of the ways dehydration can lead to weight gain)

The most obvious cause of dehydration is a lack of water. However, a few elements might influence your hydration levels and how much water you should drink daily, which varies from person to person and even from day to day based on your health and lifestyle.

The following are some of the most common causes of dehydration:

  • Diet, exercise, and activity levels, as well as alcohol intake, are all lifestyle variables.
  • Diabetes
  • Levels of Stress
  • Medications 
  • Age
  • Hormones

How to Prevent Dehydration

Dehydration is more common in hot weather or a warmer environment. In hot weather, it is important to consume enough fluids.

Similarly, activity may lead to dehydration since it causes the body to utilize more fluid and lose water through sweat.

Older folks may progressively lose part of their thirst sensation. Drinking fluids throughout the day is a good rule of thumb. When a person becomes thirsty, they may already be dehydrated.

What is an excessive amount of water?

Water toxicity occurs when the body has an excessive amount of water. This can cause vital electrolytes in the blood to be diluted, cells to enlarge, and pressure to be placed on the brain.

It isn’t easy to drink too much water. Water poisoning has occurred in persons who drank a lot of water in a short period. This might happen during endurance activities due to heat stress or when utilizing recreational substances that enhance thirst.

There is no hard and fast rule about drinking too much water. The kidneys can remove 20–28 liters of water per day. However, they can only excrete 0.8–1.0 liters per hour. Excessive drinking can be dangerous.

How do you figure out your water percentage?

You can calculate the proportion of water in your body using internet calculators. There are different formulae available. For example, the Watson Formula measures total body water in liters.

Watson men’s formula

Total body weight (TBW) in liters = 2.447 – (0.09145 x age) + (0.1074 x height in cm) + (0.3362 x weight in kilos)

Watson’s female formula

Total body weight (TBW) in liters = –2.097 + (0.1069 x height in centimeters) + (0.2466 x weight in kilos)

To calculate the proportion of water in your body, divide your total body weight (TBW) by your weight. It’s a rough estimate, but it’ll tell you if you’re in a healthy range for the proportion of water in your body.

How much water will you require? Simple answer

You lose water daily through your breath, sweat, urine, and bowel motions. To operate correctly, you must refill your body’s water supply by ingesting water-containing drinks and meals.

So, how much fluid does a normal, healthy adult in a temperate environment require? The National Academies of Sciences, Engineering, and Medicine of the United States decided that an appropriate daily fluid consumption is as follows:

  • Men should drink around 15.5 cups (3.7 liters) of fluids daily.
  • Women should drink around 11.5 cups (2.7 liters) of fluids daily.

These guidelines apply to fluids such as water, other drinks, and meals. Approximately 20% of daily fluid consumption is typically derived from meals, with the remainder derived from beverages.

Conclusion

Water makes up a vast part of the human body. The amount varies according to age, gender, and body shape, but it is normally about 60%. A person’s water balance in the body may be maintained by drinking adequate fluids throughout the day.

Water is essential for the body to function properly. It may be found in the blood, the skin, the organs, and the bones. Every cell in the body contains water, from the brain to the teeth.

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Editorial Staff

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