COLECTOMY
from a person’s faulty cognitions (erro-
neous ways of perceiving the world
and oneself). In cognitive-behavioural
therapy, the patient is helped to identify
negative or false cognitions and then
encouraged to try out new thought
strategies. For example, a patient may
be asked to keep a diary of his or her
thoughts and feelings, in order to iden-
tify triggers for distress, and may be
taught techniques for responding dif-
ferently to upsetting thoughts.
cognitive dissonance
A state of mental or emotional tension
caused by inconsistency and disagree-
ment
among
different
aspects
of a
person’s thoughts, beliefs, values, and
behaviour. (For example, a person may
buy a well-made pair of shoes but find
that they are actually very uncomfort-
able.) People may try to reduce such
tension by reinterpreting or rationaliz-
ing the situation.
(For example, the
person with the uncomfortable shoes
may persuade him self or herself that
the comfort of the shoes w ill improve
with continued wear.)
cogwheel rigidity
A term that is sometimes used for a
characteristic muscle stiffness seen in
people with
Parkinson’s disease
.
When
the limbs of an affected person are pas-
sively moved, the muscles stretch in a
series of small jerks.
coil
The common name for any of the vari-
ous types of intrauterine contraceptive
device (see
IUD; Mirena
) .
coitus
Another term for
sexual intercourse
.
coitus interruptus
A method of contraception (see
contra-
ception, withdrawal method of
)
in w hich
the man withdraws his penis from the
woman’s vagina before
ejaculation
(the
discharge
of semen)
occurs.
Coitus
interruptus is unreliable because sperm
can be released before orgasm occurs,
and it may cause
psychosexual dysfunc-
tion
in men and women.
colchicine
A drug extracted from the autumn cro-
cus (C
oichicum autumnaie
). Colchicine
is used to treat acute attacks of
gout
and
to reduce their frequency. Side effects
include vomiting and diarrhoea.
cold abscess
An
abscess
caused by infection with the
tuberculosis
bacterium. A cold abscess
does not usually produce redness and
heat, hence its name.
cold, common
A common viral infection that causes
inflammation
of the mucous
mem-
branes lining the nose and throat.
CAUSES
There are at least
200
highly contagi-
ous viruses that are known to cause the
common cold. These organisms are eas-
ily
transmitted
in
minute
airborne
droplets sprayed from the coughs or
sneezes of infected people. In many
cases, cold viruses are also spread to the
nose and throat by hand-to-hand con-
tact with an infected person,
or by
handling objects that have become con-
taminated with the virus.
SYMPTOMS AND TREATMENT
The
symptoms
of a
cold
typically
include a stuffy or runny nose, sore
throat, headache, and cough. They usu-
ally intensify over
2 4 -4 8
hours (unlike
the symptoms of
influenza,
w hich tend
to worsen rapidly over a few hours).
Most colds clear up by themselves
w ithin a week. Affected people can take
simple measures to cope with symp-
toms; for example, m ild
analgesic drugs
or
cold remedies
may help to relieve
aches and pains, and
cough remedies
can soothe a cough. Sometimes, how-
ever, infection spreads and may cause
laryngitis,
tracheitis,
acute
bronchitis,
sinusitis,
or
otitis media.
In these cases, a
bacterial infection may develop on top
of the viral infection, and
antibiotic
drugs
may be needed to treat it. (Anti-
biotics are ineffective against viruses,
so they w ill not cure colds.)
cold injury
Localized tissue damage caused by chil-
ling of part of the body. Cold injury is
distinct from
hypothermia,
w hich refers
to chilling of the whole body
The most serious form of cold injury
is
frostbite.
In this condition, an area of
skin and flesh becomes frozen, hard,
and white as a result of exposure to
very cold, dry air. Sometimes there is
restriction of the blood supply to the
affected area. Another type of injury,
immersion foot,
occurs when the legs
and feet are kept cold and damp for
hours or days. The main risk of both
conditions is that the blood flow w ill
be slowed so much that the tissues die
and, as a result, develop
gangrene
.
Less
serious forms of cold injury include
chilblains
and
chapped skin
.
cold remedies
Preparations used to relieve symptoms
of colds (see
cold, common
) .
The main
ingredient of cold remedies is usually a
m ild
analgesic drug
,
such as
paracetamol
or
aspirin
,
w hich helps to relieve aches
and pains. Other common ingredients
include
antihistamine drugs
and
decon-
gestant drugs
,
designed to reduce nasal
congestion;
caffeine
,
w hich acts as a
m ild stimulant; and
vitamin C
.
cold sore
A small skin blister, usually around the
mouth, commonly caused by a strain of
the
herpes simplex
virus called HSV
1
(herpes simplex virus type 1).
CAUSES AND SYMPTOMS
The first attack of the virus may be
symptomless; alternatively, it may cause
a flulike illness with painful mouth and
lip ulcers,
called
gingivostomatis
.
The
virus then lies dormant w ithin nerve
cells, but may occasionally be reactivat-
ed and cause cold sores.
Reactivation of the virus may occur
after exposure to hot sunshine or a cold
wind, during a common cold or other
infection,
or in women around the
time
of their
menstrual periods
.
Pro-
longed attacks may occur in people
whose im m unity to infection has been
reduced due to illness or treatment
w ith
immunosuppressant drugs
.
In many cases, an outbreak of cold
sores is preceded by tingling in the
lips, followed by the formation of small
blisters that enlarge, causing itching
and soreness. W ithin a few days the
blisters burst and become encrusted.
Most disappear w ithin a week.
TREATMENT
The antiviral drug
aciclovir
,
applied as a
cream, may prevent cold sores if used at
the first sign of tingling.
colecalciferol
An alternative name for vitamin D3 (see
vitamin D
).
colectomy
The surgical removal of part or all of
the
colon
(the major part of the large
intestine, w hich produces faeces).
WHY IT IS DONE
Partial colectomy is usually carried out
to remove damaged or distorted sec-
tions of colon. It may be performed to
C
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