Dehydration (cont.)
What are the signs and symptoms of dehydration?
The body's initial responses to dehydration are:
- thirst to increase water
intake along with
- decreased urine output to try to conserve water. 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:
The body tries to maintain cardiac output (the amount of blood that is pumped
by the heart to the body); and if the amount of fluid in the intravascular space
is decreased, the body has to increase the heart rate, which causes blood vessels to
constrict to maintain blood pressure. This coping mechanism begins to fail as
the level of dehydration increases.
With severe dehydration, confusion and weakness will occur as the brain and
other body organs receive less blood. Finally, coma and organ failure will occur
if the dehydration remains untreated.
How is dehydration diagnosed?
Dehydration is often a clinical diagnosis. Aside from diagnosing the reason
for dehydration, the healthcare provider's examination of the patient will
assess the level of dehydration. Initial evaluations may include:
- Mental status tests to evaluate whether the patient is awake, alert, and
oriented.
- Vital signs may include postural readings (blood pressure and pulse rate
are taken lying down and standing). With dehydration, the pulse rate may
increase and the blood pressure may drop because the intravascular space is
depleted of water.
Special consideration: Many people are prescribed
high blood
pressure medications called beta blockers that may prevent these compensatory
increases in the heart rate.
- Temperature may be measured to assess fever.
- Skin will be checked to see if sweat is present and to assess the degree of
elasticity (turgor). As dehydration progresses, the skin loses its water content
and becomes less elastic.
- Infants may have additional evaluations done, including checking for a soft
spot on the skull (sunken fontanelle), assessing the suck mechanism, muscle
tone, or loss of sweat in the armpits and groin. All are signs of potential
significant dehydration.
- Pediatric patients are often weighed during routine child
visits, thus a body weight measurement may be helpful in assessing how much water has
been lost with the acute illness.
Laboratory testing
The purpose of blood tests is to assess potential
electrolyte abnormalities
(especially sodium levels) associated with the dehydration. Tests may or may not
be done on the patient depending upon the underlying cause of dehydration, the severity of
illness, and the healthcare provider's assessment of their needs.
Urinalysis may be done to determine urine concentration
- the more
concentrated the urine, the more dehydrated the patient.
Next: How is dehydration treated? »
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