Important functions of Water
Up to 60 percent of our body weight is water and it is needed to keep our organs functioning. While we can live without food for several weeks, without water, death occurs in days, showing just how important it is.
THE BODY STARTS TO ABSORB WATER AS SOON AS 5 MINUTES AFTER DRINKING.
Water aids digestion
In your stomach, acidic liquid, some of which is water, helps churn and digest your food. As the processed food passes through your intestines, liquid keeps it moving easily .If you are dehydrated and food passes through the large intestine, your body absorbs water from it. This leaves stools dry and hard, causing constipation.
Hydration
Getting enough water keeps our skin plump and elastic, helps regulate body temperature, and ensures our kidneys filter out waste. If the water concentration in the blood is too high or too low, the body compensates by moving water into or out of our cells; both can be damaging.
If more water is lost than taken in, symptoms of light-headedness and tiredness can start within hours. Thirst is the body trying to correct the problem before it becomes severe. In extreme cases, dehydration causes fits, brain damage, and death.
Regulating hydration
We lose water mainly through urine, but some evaporates from the skin, or is breathed out. The kidneys regulate water levels in the body and prevent blood from becoming too concentrated or dilute. If water levels in your body tissues or cells fall, thirst is triggered.
Sensors in your heart and arteries respond when blood volume falls by 10 percent or more, and signal thirst. Drinking tops up the liquid in your blood, increasing the volume of blood. The salt concentration of blood fluid increases if excess salt is consumed, causing water to be drawn from cells. If salt concentration rises by 1 to 2 percent, thirst is triggered.
A hydrated brain
Water is vital for the brain to function. The balance between water and the substances dissolved in it is important for neurons to transmit signals effectively.
If you become dehydrated, brain tissues shrink, and it takes more effort to carry out simple tasks. Attention, mood, memory, and reaction time can be affected, and you may even become more sensitive to pain.
Moist eyes
To keep the eyes clean and comfortable, they are continually moistened with tears, the major component of which is water. Dehydration slows tear production which can leave the eyes feeling dry, irritated, and gritty.
Blood flows easily
Blood fluid (plasma) is 92 percent water. The liquid allows oxygen-carrying red blood cells, infection-fighting white blood cells, and other vital components to flow easily to where they are needed.
If dehydration is severe, the water content of your blood falls. Blood becomes thick and viscous, making it difficult for your heart to pump it around the body. This can lead to low blood pressure, dizziness, and fainting.
Pale urine
When you are well hydrated, your urine is a pale straw colour. If you drink a lot, a more dilute urine is produced .
Concentrated urine
When you are dehydrated, the kidneys reduce the amount of water excreted, retaining water in the blood. Urine gets darker in colour due to substances dissolved in the urine becoming more concentrated.
How much of water I need
The amount of water you need varies depending on the climate and what you spend your time doing. Eight glasses per day (2–3 /liters) is frequently advised for moderately active people in temperate climates, but this includes fluid from other drinks and food. For young, healthy people, the best thing to do is to listen to your body and drink when you feel thirsty! However, elderly people can become dehydrated without feeling thirsty, and so must watch their water intake.