Water is literally everywhere. From the vast ocean bodies to the microscopic cell, it undeniably plays a very important role in our lives. In fact, around 55-60% of the human body is water. But have you ever wondered what would happen if you don’t drink water? The obvious and short answer is – you die. But if you wanted to know what changes undergo in your body due to lack of water, you’ve come to the right place. But first, let us understand the role of water in our body.
So have you ever wondered why do we need to drink water?
Water has primarily three functions in our body:-
Around 92% of our blood is water. But you would be surprised to know that water is not only present in our blood; our brain and heart are almost 75% water! (This is roughly equivalent to the moisture content in a banana. ) Lungs are around 83% water and our bones are 31% water (you read that correct).
A quick question comes to our mind is that how do we lose so much water when we and the environment around us mostly comprises of water?
Each day our body loses around 2-3 litres of water through sweat, urine, breathing and bowel movements. So we definitely need to replenish the water content in our body.
So what actually happens in the body when you don’t drink water?
When the water level in our body is low, the sensory receptors in the brain’s hypothalamus region signals the release of anti-diuretic hormone. (The hypothalamus is a small area in the centre of the brain which has to perform many important functions which include maintaining the hormonal balance and body temperature among several others.) The anti-diuretic hormone (ADH) tells the kidneys how much water to conserve. It basically maintains the water equilibrium in our body. The increase in ADH production when the water level in body is low leads to higher retention of water in the kidneys and thus a more concentrated urine so that the body does not become dehydrated.
Dehydration causes a significant change in the energy, mood and cognitive abilities of the person. A dehydrated person would find it difficult to grasp a concept and would be delirious. A water replenished brain works twice as efficient as compared to a dehydrated one. As stated earlier, the brain is 75% water. Thus during dehydration, the brain also temporarily shrinks.
Hence, if a person stopped drinking water he would undergo dehydration. He/She would first experience dry mouth followed by an itchy skin. This would be followed by reduction in brain cognitive functions such as critical thinking and grasping followed by nausea and shivering. Since our body is much less resistant to dehydration as compared to hunger, a complete absence of water would eventually lead to organ failure and finally death.
Now, you learnt about dehydration but did you know that over consumption of water is also harmful to our body? Overhydration on the other hand is increased consumption of water in a short period of time. While we need water to survive, over consumption of it may be hazardous to us. An overhydrated brain in contrast to dehydration suppresses the production of ADH or even stopping it completely. This leads to a very dilute urine. Overhydration also leads to swelling up of the human cells. In extreme cases, overhydration might lead to kidneys being filled with water which can cause headaches, seizures or even death. Overhydration while rare, is mostly seen in the case of athletes who consume lot of water in a short period of time.
So how much water do we need for maintaining equilibrium in our body?
We have always heard that we should consume at least 8 glasses of water in a day. But the actual amount of water that a person needs to drink actually depends upon the body weight as well as the environmental conditions. A person living in an arid region should consume more amounts of water in comparison with someone living in a humid environment. It has been estimated that an average male needs to consume around 2.5-3.7 litres of water while an average female needs to consume 2-2.7 litres of water. Another interesting fact is that our diet makes up for about 1/5th of our water requirements in a day. Fruits and vegetables like watermelon and strawberries are mostly made of water and thus help in providing the required water consumption while providing valuable nutrients to our body.
Maintaining a healthy water content in our body has shown to have many long term benefits. These include lower chance of stroke, help in keeping diabetes under check as well as reducing the risk from some types of cancer.
There is no denying that water is one of the most essential thing in our day to day life and having a healthy amount of water influences the way we feel, think or function for the day. As quoted by Leonardo Da Vinci –
”Water is the driving force of all nature.”