Diabetes Insipidus
What
is it?
Diabetes insipidus is a metabolic disorder that
causes the patient to produce enormous quantities
of urine accompanied by excessive thirst. DI
should not be confused with diabetes mellitus,
which results from insulin deficiency or
resistance. Diabetes insipidus and diabetes
mellitus are unrelated, although they can have
similar signs and symptoms, like excessive thirst
and urination.
Who
gets it?
Diabetes insipidus most frequently occurs in
persons in their 20s, more often in males than
females. The disorder may run in families, though
the cause is unknown. Diabetes insipidus can occur
after an injury to the head; brain surgery;
cancer; sarcoidosis, causing destruction of the
pituitary gland; the use of certain medications
that decrease ADH production; excessive use of
alcohol; and any condition or illness that causes
decreased oxygen delivery to the brain. Diabetes
insipidus may also occur in women who are pregnant
or have just given birth, and in patients with
AIDS who have suffered certain types of brain
infections.
What
causes it?
Diabetes insipidus is caused by the deficient
production or secretion of the antidiuretic
hormone (ADH) or the inability of the kidney
tubules to respond to ADH. This hormone is made in
the hypothalamus, a small gland located in the
base of the brain. ADH is stored in the nearby
pituitary gland and released from it into the
bloodstream when necessary. When ADH reaches the
kidneys, it directs the kidneys to concentrate the
urine by returning excess water to the bloodstream
and therefore make less urine.
What
are the symptoms?
Symptoms of Diabetes insipidus include extreme
thirst and the production of excessive
quantities of urine. When the amount of water
passed in the urine exceeds the patient's ability
to drink enough replacement water, the patient may
begin to suffer from symptoms of dehydration.
Symptoms of dehydration include weakness, fatigue,
fever, low blood pressure, increased heart rate,
dizziness, and confusion.
How is
it diagnosed?
Diabetes insipidus is diagnosed through a water
deprivation test which reveals very dilute urine,
made up mostly of water with no solute.
Examination of the blood will reveal very
concentrated blood, high in solute and low in
fluid volume.
What
is the treatment?
In mild
cases no treatment is necessary. A number of
medications can be given to decrease the quantity
of fluid passed out into the urine, including
Pitressin and DDAVP. Other medications that may be
given include some antidiuretis.
Self-care tips
Careful
monitoring of the patient is essential when the
condition is suspected, especially
after head surgery or trauma. Uncomplicated
diabetes insipidus is controllable with adequate
intake of water and most patients can lead normal
lives.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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