Webster's New World Medical Dictionary

109
deformation
05_189283 ch04.qxp 4/18/08 10:14 PM Page 109
http://www.rashidislamiccenter.com
http://www.allofislam.com/

---

vaginal delivery. A deformation is different from a
malformation in both timing and impact. See also
malformation.
degeneration, macular
See 
macular degener-
ation.
degenerative arthritis
See 
arthritis, degenera-
tive.
degenerative joint disease
See 
arthritis,
degenerative.
deglutition
The act of swallowing, particularly of
swallowing food. The muscles of deglutition are the
muscles employed in the act of swallowing.
dehisce
To burst open or gape. A surgical wound
may partially or completely dehisce after surgery,
depending upon whether some or all of the layers of
tissue come open.
dehydration
Excessive loss of body water.
Diseases of the gastrointestinal tract that cause vom-
iting or diarrhea may lead to dehydration. There are
a number of other causes of dehydration, including
overheating (hyperthermia), prolonged vigorous
exercise (as in a marathon), kidney disease, and
medications (diuretics). One clue to dehydration is
a rapid drop in weight. Symptoms include increasing
thirst, dry mouth, weakness or lightheadedness
(particularly when it worsens on standing), and a
darkening of or decrease in urination. Severe dehy-
dration can lead to changes in the body’s chemistry,
kidney failure, and death. Intravenous or oral fluid
replacement may be needed in some cases. See also
diarrhea; hyperthermia.
dehydroepiandrosterone
Also DHEA; a steroid
hormone made by the adrenal glands, that acts on
the body much like testosterone and is converted
into testosterone and estrogen. The blood levels of
DHEA decline with age. DHEA is sold in the US with-
out a prescription as a “nutritional supplement.” It
has been claimed to improve mood, boost the
immune system, sharpen memory, and combat
aging.
déjà vu
A disquieting feeling of having been
somewhere or done something in the past, even
though one has not. Although most people have
experienced this feeling at one time or another, in
some people sensations of déjà vu are part of a
seizure or migraine aura; in others, the sensations
are a seizure phenomenon. See also 
jamais vu;
seizure disorder.