It is difficult for humans to survive without food and water for a longer duration. About 60% of the adult body is made of water. It is easy to survive without food for about three weeks but one can only last three to four days without water.

It is impossible to survive on air and sunshine alone. A major part of our body is composed of water and every living cell in the body needs water to keep functioning. Water has an important role to play in our bodies. It acts as a lubricant that keeps our joints flexible and moving, helps to flush waste and regulates our body temperature through sweating and respiration.

According to studies, the maximum time an individual can go without water seems to be a week. This time may vary according to the temperature around us. It is difficult to survive in high temperature for a few hours. While for places that are cool, you can go a little longer.

Our body needs water to perform many functions. It is needed by our brain to manufacture hormones, to form saliva that helps in digestion, helps to regulate the body temperature , helps in respiration, presence of water allows body cells to grow, reproduce and survive, helps to deliver oxygen throughout our body, keeps our joints lubricated , converts food into small components and flushes body waste through urine.

We lose water when we urinate, sweat and even when we exhale. Our bodies go through a continuous process of losing water, which is why we need to drink water repeatedly and keep the body replenished.

Experts say that under extreme conditions an adult can typically lose between 1 to 1.5 liters of sweat per hour. The lost water has to be replaced. If it is not replaced, the total volume of body fluid can fall quickly and, lead to a drop in blood volume. If the blood volume drops, blood pressure falls to levels that can be fatal. Body temperatures also rise when we stop sweating.

One needs to take proper intake of fluids if suffering from Dehydration. Dehydration causes a loss of more than 10% of your body weight. If not cured on time, it can lead to death.

Water Sources
Experts say that one should consume at least 5 to 6 liters of water every day. If you are not able to drink water, keep yourself hydrated by sipping fresh juices, milk or coconut water. It is better to stay away from alcohol. Consuming alcohol causes the body to lose more water than normal through excessive urination.
Although, we get water from food, but that is not enough to fulfill our daily requirement. Water cannot be replaced and must be drunk in enough quantity to refill our bodies.