- Water is an essential component of the human body. The human body is made up of about 43% to 75% of water - depending on age, body fat, etc [if fat is taken out of consideration, the nominal water content is about 72% of body mass - according to this source]. You could probably survive for 4 to 8 weeks without food (source), but it is estimated that lack of water could cause death in about 10 days, at room temperature (source).
- Water acts as a nourishing agent. Water circulates through the blood and helps transport nutrients and oxygen towards organs and cells. It acts as a solvent for many nutrients and essential salts and makes them available for absorption by the body.
- Water is a cleansing agent. It also serves as a medium to carry metabolic wastes away from the body - this is accomplished in the form of urine and sweat. Think of it as a detoxifying agent. This is one of the most important functions of water in our body (although not very highly appreciated often in daily life).
- Water helps reduce the risk of kidney stones. The kidneys filter out waste products from the blood and channel them out of the body through the process of urine formation. Increasing concentration of certain salts in the urine increases the risk of kidney stone formation - and in most cases this risk can be reduced by drinking a lot of water and diluting the urine. It is usually recommended that adults prone to kidney stones should try to drink about 12 eight-ounce glasses of water everyday (normal adult recommendation is about 8 glasses).
- Water helps reduce the risk of sunstroke. Water is the single most important factor in the highly critical function of regulating your body temperature. On sunny days, we sweat (in other words - excrete water) more and the evaporation of the sweat has a cooling effect on the body. In the absence of sufficient water (when dehydration occurs) in your body, this temperature regulation breaks down and body temperature increases - and this leads to sunstroke. Severe sunstroke has the potential to damage your vital organs.
- Water helps lower the blood pressure. When you lose more than optimal levels of fluid due to various conditions (not drinking sufficient water, heavy exercise, illness, etc), the body tries to adjust for the loss of water by constricting blood vessels so that the rate of loss of water (due to sweating and respiration) is reduced - which in turn leads to higher blood pressure. Drink ample water to prevent this from happening. Of course, this is applicable when the higher blood pressure has been attributed to the lack of enough fluids in the body [don’t confuse this with special diuretic treatments for certain heart, liver, and kidney conditions - in which sometimes it is necessary to remove excess fluids from the body to lower the blood pressure].
- Water minimizes the risk of heart disease. This follows from the the above point - increased dehydration causes your cells and tissues to absorb water from the blood stream and thus decreases the volume of the blood flow (probably that’s why constriction of blood vessels and the subsequent increase in blood pressure occurs - read #6). Increased blood pressure is a sign of a heart that’s working harder than it should - it tries to pump more blood to excretory organs to compensate for the reduced volume. This could probably worsen a heart related ailment. Sufficient water intake will ensure that this does not happen.
- Water keeps your skin in good condition. In the process of sweating, it also removes impurities in the skin and cleanses it - leaving you with a healthy and younger looking skin. Dehydrated skin cells can cause your skin to appear wrinkled or sagging.
- Water does not contain calories. Feel free to replace those sugary soft drinks with water; water does not contain any calories - so unlike the soft drinks it’s not going to increase your weight. Some studies have pointed towards how increased water consumption can in fact cause weight loss. Americans consume about 13 billion gallons of calorific drinks every year. You can imagine the net effect that can be achieved by replacing all that with water. Make it a habit - whenever you go to a fast food joint or a restaurant, ask for water instead of a soda.
- Water suppresses appetite. This follows from the above point. Since water does not have any calories, it acts as an ideal *filler* material in your stomach and gives you a sense of “I am full” - which in turn decreases your appetite. This works best for people who are already over-weight and are controlling their appetite in order to lose weight. If you are anorexic, this isn’t for you.
10.5 BONUS - Water is (almost) free. Obviously, I am not talking about bottled water here. Most water supplied by municipal taps is good enough for drinking and comes fairly cheap. You get it for free in restaurants, fast food joints, and drinking water fountains in your workplace or school. You don’t require credit cards or cash to ask for it.
There are other more subtle but critical roles played by water. For example, read this (source):
Drinking plenty of water every day is especially important for people with bipolar disorder, because certain medications may increase your risk of becoming overheated.
It goes beyond just medications for people with bipolar disorder, it’s applicable to a lot of medicines which cause excess urination (diuretics).
The recommended daily intake of water for a normal adult is about 64 ounces or 8 full eight-ounce glasses.
Now, apparently some people have trouble consuming that much water in a day; but don’t worry, here is a solution if you have that problem.
By the way, there is a subtle difference between drinking “enough” water and drinking “excessive” water. Like all other excesses, this one also carries it’s share of troubles if you push it to the extreme. So be sensible and drink “enough” water everyday.