HYPER-
HYPERHIDROSIS
H
reduce nausea in
Meniere's disease
.
It is
also used in eye-drops to dilate the pupil
before an eye examination or surgery.
An injection of hyoscine hydrobromide
is often given as part of a
premedication
because it dries secretions in the mouth
and lungs. Possible adverse effects of
both forms include dry mouth, blurred
vision, drowsiness, and constipation.
hyper-
A prefix meaning above, exces-
sive, or greater than normal.
hyperacidity
A condition in which ex-
cess acid is produced by the stomach.
Hyperacidity is often confused with
acid
reflux
or
waterbrash
.
It occurs in people
with a duodenal ulcer (see
peptic ulcer)
or
Zollinger-Ellison syndrome
.
hyperactivity
A behaviour pattern in
which children are overactive and have
difficulty in concentrating. The occasional
occurrence of such behaviour in small
children is considered normal. However,
persistent hyperactivity is known as
attention deficit hyperactivity disorder
(ADHD)
,
which may require treatment.
hyperacusis
An excessively sensitive
sense of hearing. In hyperacusis, expo-
sure to loud noises may cause pain or
discomfort in the ears.
hyperaldosteronism
A metabolic dis-
order caused by an overproduction of
the hormone
aldosterone
by the
adrenal
glands
(see
aldosteronism
).
hyperalimentation
Administration of
excessive amounts of
calories
, usually
intravenously or by stomach tube (see
feeding, artificial)
.
hyperbaric oxygen treatment
A meth-
od of increasing the amount of
oxygen
in the tissues. This is achieved by plac-
ing a person in a special chamber and
exposing him or her to oxygen at a
much higher atmospheric pressure than
normal. Hyperbaric oxygen treatment is
used to treat poisoning from
carbon
monoxide
and in cases of gas
gangrene
.
hyperbilirubinaemia
A raised blood
level of
bilirubin
.
It may be undetectable
except by a blood test, but
jaundice
occurs if the blood bilirubin rises to
twice the normal level.
hypercalcaemia
An abnormally high
level of
calcium
in the blood, commonly
caused by
hyperparathyroidism.
Cancer
may also cause hypercalcaemia, either
by spreading to bone or producing
abnormal hormones that cause bones
to release calcium. Less commonly, the
condition is a result of excessive intake
of
vitamin D
or of certain inflammatory
disorders, such as
sarcoidosis.
Hypercalcaemia causes nausea, vom-
iting, lethargy, depression, thirst, and
passing urine excessively. Higher blood
levels of calcium produce confusion,
extreme fatigue, and muscle weakness.
Without treatment, the condition can re-
sult in cardiac
arrhythmias, kidney failure,
coma,
and even death. Long-standing
hypercalcaemia may cause
nephrocalci-
nosis
or kidney stones (see
calculus,
urinary tract).
Diagnosis is by
blood tests.
Treatment is of the underlying cause.
hypercapnia
Excessive carbon dioxide
in the blood caused by failure of mech-
anisms, such as
breathing
rate, that
normally control the carbon dioxide
levels in the blood. Hypercapnia leads
to respiratory
acidosis
.
hyperemesis
The
medical
term
for
excessive
vomiting
, which may cause
dehydration and weight loss. When the
condition occurs in pregnancy, it is
known as hyperemesis gravidarum.
hyperglycaemia
An abnormally high
level of
glucose
in the blood that occurs
in people with untreated or inadequately
controlled
diabetes mellitus
. Hyperglycae-
mia may also occur in diabetics as a
result of an infection, stress, or surgery.
Features of the condition include passing
large amounts of urine, thirst,
glycosuria
,
and
ketosis
. If severe, hyperglycaemia
may lead to confusion and
coma
, which
need emergency treatment with
insulin
and
intravenous infusion
of fluids.
hypergonadism
Overactivity of the go-
nads (
testes
or
ovaries
) that results in
overproduction of
androgen hormones
or
oestrogen hormones
. Hypergonadism
may be due to disorders of the gonads
or a disorder of the
pituitary gland
that
results in overproduction of
gonado-
trophin hormones
. During childhood,
the condition causes precocious sexual
development and excessive growth.
hyperhidrosis
Excessive
sweating
, which
may be localized (affecting only the arm-
pits, feet, palms, or face) or affect all
body areas supplied by
sweat glands
.
290
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