around the eyelids, and severe muscle
pains, which may last for several weeks.
Trichinosis may be suspected from the
symptoms, and the diagnosis is con-
or by a muscle
. Treatment of the infestation is
trichomoniasis An infection caused by
protozoan trichomonas vaginalis.
Trichomoniasis is a common cause of
In some cases, the infection is
In women, the causative organism
may inhabit the
for years without
causing symptoms. If symptoms occur,
they include painful inflammation of
the vagina and
, and a greenish,
frothy, offensive-smelling discharge. Men
usually have no symptoms.
The diagnosis is made from exami-
nation of a sample of the discharge.
Diagnosis usually difficult in men. Treat-
ment is with
. The sexual
partner or partners of an infected per-
son should be treated at the same time
to prevent reinfection.
trichotillomania The habit of cons-
tantly pulling out one's hair. It can be
associated with severe
or with a psychotic illness. It may also
occur in psychologically disturbed chil-
dren. The sufferer typically pulls, twists,
and breaks off chunks of hair from the
scalp, leaving bald patches; occasionally,
pubic hair is pulled out. Children some-
times eat the removed hair, which may
form a hairball in the stomach, known
medically as a trichobezoar (see
Treatment depends on the cause, and
may consist of
trichuriasis A parasitic infestation with
the tropical worm
(whipworm). Children are most com-
monly affected. Infestation occurs when
eggs are ingested and develop into
adult worms in the intestines. Severe
infestation may cause bloody diarrhoea,
abdominal pain, and weight loss. Treat-
ment is with
tricuspid incompetence Failure of the
to close fully, allowing
blood to leak back into the right atrium
when the right ventricle contracts. The
STRUCTURE OF HEART
is also known as
iency, reduces the
ency of the heart.
The usual cause is
, but more
or, in intravenous
drug users, a bac-
terial infection of
petence results in
symptoms of right-
the ankles and abdomen. The liver is
swollen and tender, and veins in the
neck are distended.
A diagnosis is made from the symp-
toms, from hearing a heart
through a stethoscope, and by tests that
may include an
often relieves the symptoms.
tricuspid stenosis Narrowing of the
opening of the
caused by a previous attack of
. Tricuspid stenosis is uncommon
and often occurs with another heart-
valve disorder. For example,
may also occur in intra-
venous drug users who have a bacterial
infection of the heart. Tricuspid stenosis
causes enlargement of the right atrium.
The symptoms and diagnosis are simi-
lar to those of tricuspid incompetence.
Treatment is with
digitalis drug. Heart-valve
is sometimes needed.
tricuspid valve A valve in the
consisting of 3 flaps that lies between
the right atrium and the right ventricle.
It ensures that blood flow from the atri-
um to the ventricle is in
tricyclic antidepressants A type of
brain from being reabsorbed, thereby
increasing their level. Examples are