what percentage of human body is water what percentage of human body is water

What Percentage of Human Body is Water?

Have you ever thought about what percentage of human body is water? The usual amount of water in the body ranges from 45-75%. The average percentage of water in the person’s body varies according to age, gender, weight, health, and where the person resides.

Nevertheless, water is vital for every living organism existing on the Earth because the body mostly comprises water. Usually, an adult male requires 3 litres of water per day whereas, an adult female needs approximately 2.2 litres of water in a day. This article is all about finding out what percentage of human body is water.

Functions of Water in The Body

Before concluding the answer of what percentage of the human body is water, let us understand the significance of water in the body. Water is beneficial for life because it is responsible for carrying out various functions of the body. For instance:

  1. Water is the primary building block of cells and a key component on which every cell depends on its survival.
  2. It is a building block of vital molecules of the body, such as hormones and neurotransmitters.
  3. It helps the body excrete waste, mainly through urine and sweat.
  4. It behaves as an insulator and helps in regulating internal body temperature. This is because water has high heat storage, and the body utilizes perspiration and respiration to maintain healthy body temperature.
  5. It Keeps the membranes of the body moist. For example, it keeps the eyes clear and hydrated and facilitates swallowing food and the excretion of faeces.
  6. It is required to metabolize proteins and carbohydrates because water is the fundamental unit of saliva, crucial for digesting and swallowing food.
  7. It insulates organs of the body like the brain, spinal cord, and fetus by acting as the shock absorber and lubricates joints.
  8. It is the principal solvent in the body because it dissolves minerals, some nutrients, and vitamins.
  9. It is a transporter of oxygen and nutrients to cells.
  10. It is crucial when a woman becomes pregnant because water becomes an important component of amniotic fluid that comforts and protects the growing fetus.

What Percentage of Human Body is Water?

what percentage of human body is water
Image by mohamed Hassan from Pixabay

During the first few months of life, approximately three-fourths of the body is composed of water, and it starts declining as the body grows. For example, 78% of the newborn’s body is made of water. The reason for the declining percentage of water in the body is the deposition of a large amount of fatty tissue and less fat-free mass as the person grows. For example, by one year of age, the amount of percentage of water decreases to 65%

What percentage of human body is water is an important question. Fatty tissues present in the body contain less water as compared to lean tissue. Adult women’s body has more fatty tissue, so 55% of their bodies are made of water. At the same time, around 60% of the body is water in adult men due to less body fat1.

Older adults begin to lose body water percentage because they become more susceptible to hydration2. The body of an average adult male above 51 years of age is about 51% water, while the body of an average adult female of the same age is about 47% water.

The body of overweight men and women contains less water in comparison to normal-weight men and women. Therefore, body weight and body composition affect the percentage of water in the body.

The percentage of water in the human body also depends upon the hydration level. People feel thirsty when they lose approximately 2-3% of their body’s water. Consuming only 2% water will impair mental health and physical coordination.

Though water is the most abundant molecule in the body, extra water is stored in hydrated compounds. Around 30-40% of the body’s weight is due to the skeleton, but half the weight is lost when the bound water is eliminated, either by chemical extraction or sweat.

Therefore, this gives a person an idea of what percentage of the human body is water to think twice before forgetting to drink water. 

Location of Water in the Human Body

After answering the question of what percentage of the human body is water, it is mandatory to know the location of water in the human body. Approximately two-thirds of the body’s water is found inside cells of the body (intracellular fluid, ICF3), one-third of the water is present outside the cells of the body (extracellular fluid, ECF4), and around 20% of the body’s water is present in the blood plasma.

The amount of water stored varies with different organs. Out of all the parts of the body, bones contain a low amount of water (31%), the skin contains 64% water, muscles and kidneys have 70% water, the human brain and heart separately contain 73% water, and the lungs contains a high percentage of water (79%).

How To Maintain the Percentage of Water In The Human Body?

Understanding what percentage of the human body is water and then how to maintain that percentage is necessary. Several factors like gender, age, health, and type of lifestyle also affect the amount of water one drinks to maintain the ideal hydration level of the body. According to The United States Geological Survey, men require about 3.2 quarts of water every day, and women need 2.3 quarts of water every day.

Getting the required water depends on the food and beverages one takes each day. The more water and fluids a person consumes, the more urine is produced in the kidneys. The body naturally tries to maintain the water level by eliminating excessive water in urine.

If a person fails to drink enough water, less urine will be produced by the kidneys because the body tries to conserve fluids and maintain the proper water level. A very low water consumption increases the risk of dehydration and harms the body afterward.

A person consumes water in different ways. For instance, the consumption of a glass of orange juice is entirely water. Similarly, caffeinated beverages, such as tea, coffee, or soda, contain a high amount of water, but the caffeine makes the person urinate more often.

Certain foods that contain a high percentage of water can also help the person to stay hydrated. Examples include strawberries, citrus fruits, lettuce, spinach, cucumbers, and skim milk.

Read more about what percentage of the human body is water

A Take-Home Message

what percentage of human body is water
photo by Snapwire from pixels

Water serves various functions of the body. A major portion of the human body is composed of water, so a lower body water percentage can lead to dehydration and related health problems that can become risky for individuals. Thereby, it is vital to be aware of the functions, what percentage of the human body is water, and the storage space of water in the body.

  1. Luke, Amy. “Ethnicity and the BMI–body fat relationship.” British journal of nutrition 102.4 (2009): 485-487. ↩︎
  2. Popkin, Barry M., Kristen E. D’Anci, and Irwin H. Rosenberg. “Water, hydration, and health.” Nutrition reviews 68.8 (2010): 439-458. ↩︎
  3. Lin, Yao-Ping, et al. “The extracellular fluid—to—intracellular fluid volume ratio is associated with large-artery structure and function in hemodialysis patients.” American journal of kidney diseases 42.5 (2003): 990-999. ↩︎
  4. Maurer, Martin H. “Proteomics of brain extracellular fluid (ECF) and cerebrospinal fluid (CSF).” Mass spectrometry reviews 29.1 (2010): 17-28. ↩︎

Last Updated on by Sanjana


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