Dehydration
Dehydration occurs when you use or lose more
fluid than you take in, and your body doesn't have enough water and other
fluids to carry out its normal functions. If you don't replace lost fluids, you
will get dehydrated. Anyone may become dehydrated, but the condition is
especially dangerous for young children and older adults. The most common cause
of dehydration in young children is severe diarrhea and vomiting. Older adults
naturally have a lower volume of water in their bodies, and may have conditions
or take medications that increase the risk of dehydration.
Causes
The
basic causes of dehydration are not taking in enough water, losing too much
water, or a combination of both. Sometimes, it is not possible to consume
enough fluids because we are too busy, lack the facilities or strength to
drink, or are in an area without potable water (while hiking or camping, for
example). Additional causes of dehydration include:
Diarrhea - the most common cause of
dehydration and related deaths. The large intestine absorbs water from food
matter, and diarrhea prevents this from happening. The body excretes too much
water, leading to dehydration.
Vomiting - leads to a loss of fluids and
makes it difficult to replace water by drinking it.
Sweating - the body's cooling mechanism
releases a significant amount of water. Hot and humid weather and vigorous
physical activity can further increase fluid loss from sweating. Similarly, a
fever can cause an increase in sweating and may dehydrate the patient, especially
if there is also diarrhea and vomiting.
Diabetes - high blood sugar levels cause
increased urination and fluid loss. Tips for handling summer heat for people
with diabetes.
Frequent urination - usually caused by uncontrolled
diabetes, but also can be due to alcohol and medications such as diuretics,
antihistamines, blood pressure medications, and antipsychotics.
Burns - blood vessels can become
damaged, causing fluid to leak into the surrounding tissues.
Symptoms
The
body's initial responses to dehydration are thirst to increase water intake,
and decreased urine output to try to conserve water loss. The urine will become
concentrated and more yellow in color.
As
the level of water loss increases, more symptoms can become apparent. The
following are further signs and symptoms of dehydration.
·
Infant
or young child
·
Dry
mouth and tongue
·
No
tears when crying
·
No
wet diapers for three hours
·
Sunken
eyes, cheeks
·
Sunken
soft spot on top of skull
·
Listlessness
or irritability
·
Adult
·
Extreme
thirst
·
Less
frequent urination
·
Dark-colored
urine
·
Fatigue
·
Dizziness
·
Confusion
Complications
Dehydration
can lead to serious complications, including:
Heat
injury. If you don't drink enough fluids
when you're exercising vigorously and perspiring heavily, you may end up with a
heat injury, ranging in severity from mild heat
cramps to heat exhaustion or potentially life-threatening heatstroke.
Urinary
and kidney problems. Prolonged or repeated bouts of
dehydration can cause urinary tract infections, kidney stones and even kidney
failure.
Seizures. Electrolytes — such as potassium
and sodium — help carry electrical signals from cell to cell. If your
electrolytes are out of balance, the normal electrical messages can become
mixed up, which can lead to involuntary muscle contractions and sometimes to a
loss of consciousness.
Low blood volume
shock (hypovolemic shock). This is one of the most serious,
and sometimes life-threatening, complications of dehydration. It occurs when
low blood volume causes a drop in blood pressure and a drop in the amount of
oxygen in your body.
Diagnosis
A
doctor will use both physical and mental exams to diagnose dehydration. A
patient presenting symptoms such as disorientation, low blood pressure, rapid
heartbeat, fever, lack of sweat, and inelastic skin will usually be considered
dehydrated. Blood tests are often employed to test kidney function and to check
sodium, potassium, and other electrolyte levels. Electrolytes are chemicals
that regulate hydration in the body and are crucial for nerve and muscle function.
A urine analysis will provide very useful information to help diagnose
dehydration. In a dehydrated person, urine will be darker in color and more
concentrated - containing a certain level of compounds called ketones. To diagnose dehydration in infants, doctors
usually check for a sunken soft spot on the skull. They may also look for a
loss of sweat and certain muscle tone characteristics.
Treatments
Dehydration
must be treated by replenishing the fluid level in the body. This can be done
by consuming clear fluids such as water, clear broths, frozen water or ice
pops, or sports drinks (such as Gatorade). Some dehydration patients, however,
will require intravenous fluids in order to rehydrate. People who are
dehydrated should avoid drinks containing caffeine such as coffee, tea, and
sodas. Underlying conditions that are causing dehydration should also be
treated with the appropriate medication. This may include medication available
to purchase over-the-counter or online, such as anti-diarrhea medicines, anti-emetics
(stop vomiting), and anti-fever medicines.
Prevention
To
prevent dehydration, drink plenty of fluids and eat foods high in water such as
fruits and vegetables. Letting thirst be your guide is an adequate daily
guideline for most healthy people. People may need to take in more fluids if
they are experiencing conditions such as:
Vomiting
or diarrhea. If your child is vomiting or has
diarrhea, start giving extra water or an oral rehydration solution at the first
signs of illness. Don't wait until dehydration occurs.
Strenuous
exercise. In general, it's best to start
hydrating the day before strenuous exercise. Producing lots of clear, dilute
urine is a good indication that you're well-hydrated. During the activity,
replenish fluids at regular intervals and continue drinking water or other
fluids after you're finished.
Hot
or cold weather. You need to drink additional
water in hot or humid weather to help lower your body temperature and to
replace what you lose through sweating. You may also need extra water in cold
weather to combat moisture loss from dry air, particularly at higher altitudes
Illness. Older adults most commonly become
dehydrated during minor illnesses — such as influenza, bronchitis or bladder
infections. Make sure to drink extra fluids when you're not feeling well.