WATER: Are You Drinking Enough?
Water is so essential that humans can die within a matter of a few days, if they are completely deprived of it.
Health experts recommend drinking six (6) to eight (8) glasses each day, along with other drinks.
This is, however, a general average and in some cases an individual may require more than eight glasses per day. It depends on an individual’s body mass index (BMI), and the amount of fluid loss due to physical activity or health
conditions such as kidney stone.
It is estimated that many
people do not drink enough and are consequently slightly dehydrated. This
can result in symptoms such as headaches, irritability and forgetfulness.
It can also place a strain on the kidneys and result in urinary tract infections
and kidney stones. The thirst sensation of older persons can diminish and
hence the elderly are at particular risk of dehydration, as are small children.
Even before birth, fluids play an integral part in our sustenance and
development. We consume it from our mothers and spend many months floating
in amniotic fluid. At birth, as much as 75% of a baby’s weight is made up of
water. As we grow older, however, this tends to decrease. For example, in
young adult male it accounts for an average of 55% to 60% of body weight while
women average slightly less. Obese and elderly persons can average as low as
45%.
As we continue to grow and develop after birth, fluid is continually
exchanged between compartments within our bodies, by way of capillary walls and
plasma membranes. Water moves by osmosis from the digestive tract to the
bloodstream. It is then distributed from the blood to the tissue fluid by
a process known as capillary filtration. Osmosis
from one fluid compartment to another is determined by the relative
concentration of solutes in each compartment. The
direction of osmosis, therefore, will be from a more dilute solution to a more concentrated one.
A person is said to be in a state of water-balance when
daily gains and losses are equal. Losses occur daily in urine, faces,
breathing, sweat, and cutaneous transpiration. Cutaneous transpiration
is not the same as sweat. A simple way to observe it is to place the palm of
your hand on a cool nonporous surface, such as a mirror. When you remove your
hand, you will notice the condensed-water that transpired through the skin, on the surface of the mirror.
You might be asking, "what is the main purpose-of-water and why does the body need so much of it?" Well, basically, it helps to maintain the
right volume and concentration of blood and other fluids within the body, but
its comprehensive function extends a bit beyond this. It contains a set of properties
that facilitates proper biological functions. These properties include
solvency, cohesion, adhesion, chemical reactivity, and thermal stability.
Solvency is the ability to dissolve other chemicals. Water is sometimes
referred to as the universal solvent because it dissolves a broader range of
substances than any other liquid. This is very important since biological
molecules within the body must be dissolved in order to move freely, bond
together, and perform their functions.
Adhesion is the tendency of one substance
to cling or bind to other substances. This is different from cohesion,
which is the tendency of molecules of the same substances to cling to each
other. Adhesion forms a lubricating film on membranes within the body that
helps reduce friction. An example of this is when the lungs and heart contract
and expand and rub against these membranes.
Chemical reactivity is the ability to
participate in chemical reactions - many chemicals such as acid and salt are
ionized . Thermal stability is the ability to help stabilize the
internal temperature of the body.
FLUID DEFICIENCY
Fluid intake is governed mainly by thirst. The body is in
a state of fluid imbalance if there is abnormal fluid concentration, fluid
volume, or fluid distribution among different compartments in the body. Fluid
deficiency occurs when output exceeds intake, over an extended period of time.
There are two kinds of deficiency – volume depletion and dehydration.
Volume depletion is known as hypovolemia and occurs
when proportionate amounts of water-and-sodium are lost without being replaced.
This occurs mainly in cases of hemorrhage, burns, chronic vomiting, or
diarrhea. A less common cause is aldosterone hyposecretion (Addison disease),
which results in inadequate sodium and water-reabsorption.
Dehydration is different from volume depletion in
that the body eliminates significantly more water than sodium. The most common
cause of dehydration is simply not drinking enough fluids. Other causes include
diabetes mellitus, ADH hyposecretion (diabetes insipidus), and profuse
sweating. It should be noted that prolonged exposure to cold weather can be a
cause of dehydration, just as much as prolonged exposure to hot whether.
The most serious effect of volume depletion and dehydration
are circulatory shock, due to loss of blood volume and neurological dysfunction,
due to dehydration of brain cells.
FLUID EXCESS
Fluid excess is less common than fluid deficiency. This is
because the kidneys are very effective at compensating for excessive fluid
intake, by producing more urine. This is one of the main functions of the kidney. When the kidneys are not functioning properly, however, this usually
leads to excessive fluid retention.
Fluid excesses are of two types – volume excess and hypotonic hydration.
With volume excess, both water-and-sodium are retained. This is commonly
caused by renal failure. With hypotonic hydration (also called water-intoxication), more water than sodium is retained or ingested. Fluid
excesses can result in pulmonary or cerebral edema (or oedema) which is the
gathering of fluid in the lungs or brain.
There is no question that adequate consumption-of-water is important, but it is also important to pay attention to the quality. Filters and other
purification systems have become increasingly popular in recent years. While
most of these purification devices are able to remove some pollutants,
unfortunately they can also remove compounds such as minerals that may be
beneficial to health. Bottled-waters are widely available and are a popular
alternative. Although most of them are safe to drink, they are not all
necessarily free of compounds and additives.
Water is
essential for biological functions and must be continuously replenished, as it
is constantly lost mainly through urination, respiration, and sweating. An
average adult requires between two (2) to three (3) liters daily, depending on
body size and weight. Persons with kidney stones,
severe diarrhea, or any bout of sickness where dehydration poses a particular
risk should drink plenty of fluids-and-water, especially in frequent sips.
How many glasses have you had today? Why not have a refreshing glass right now.
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