The causes of anorexia are unclear, but
the condition may be linked to a lack of
self-worth that leads to excessive con-
cern over physical appearance. Normal
dieting may develop into starvation.
In the early stages, sufferers may be
overactive and exercise excessively.
They are obsessed with food, and often
make complicated meals for their fami-
lies, but are reluctant to eat socially and
manage to avoid eating the meals
themselves. As weight loss continues,
they become tired and weak, the skin
becomes dry, lanugo hair (fine, downy
hair) grows on the body, and normal
hair becomes thinner. Starvation leads
to amenorrhoea in many women. Some
anorexics sometimes make themselves
vomit or take laxative drugsor diuretic
drugs to promote weight loss (see
bulimia). Chemical imbalances as a
result of starvation with or without
vomiting can cause potentially fatal car-
diac arrhythmias.
Hospital treatment is often necessary
and is usually based on a closely con-
trolled feeding programme, combined
with psychotherapyor family therapy.
For some people, antidepressant drugs
may be helpful. Many sufferers relapse
after treatment, and long-term psycho-
therapy is required.
anorgasmiaInability to achieve orgasm
(see orgasm,lack of).
anosmiaLoss of the sense of smell.
anoxiaA complete absence of oxygen
in a body tissue. Anoxia causes disrup-
tion of cell metabolismand cell death
unless corrected within a few minutes.
Anoxia occurs during cardiopulmonary
arrest or asphyxiation and will cause
permanent organ damage or even death
if not corrected. (See also hypoxia.)
antacid drugsDrugs taken to relieve
the symptoms of indigestion, heartburn,
oesophagitis, acid reflux, and peptic ulcer.
Antacids usually contain compounds of
magnesiumor aluminium, which neutra-
lize stomach acid. Some also contain
alginates, which protect the lining of
the oesophagus from stomach acid, or
dimeticone, an antifoaming agent, which
helps to relieve flatulence.
Aluminium may cause constipation
and magnesium may cause diarrhoea;but these effects may be avoided if a
preparation contains both ingredients.
Antacids interfere with the absorption
of many drugs and should not be taken
at the same time as other drugs.
antagonistHaving an opposing effect.
For example, antagonist drugs counter-
act the effects of naturally occurring
chemicals in the body. (see also agonist.)
antenatal careThe care of a pregnant
woman and her unborn baby through-
out a pregnancy. Such care involves
regular visits to a doctor or midwife,
who performs abdominal examinations,
blood and urine tests, and monitoring
of blood pressure and fetal growth to
detect disease or potential problems.
Ultrasound scanningis carried out to
identify abnormalities in the fetus. Chori-
onic villus samplingor amniocentesis
may be performed if the baby is thought
to be at increased risk of a chromosomal
abnormalityor a genetic disorder. The
woman is also advised on general asp-
ects of pregnancy, such as diet, exercise,
techniques to help her with childbirth.
(See also childbirth,natural.)
antepartum haemorrhage Bleeding
from the vagina after the 28th week of
pregnancy. Antepartum haemorrhage is
most commonly due to a problem with
the placenta, such as placenta praevia
or placental abruption. Bleeding can
also be caused by cervical erosionor
other disorders of the cervix or vagina.
Admission to hospital is necessary for
investigation and treatment. Ultrasound
scanningis used to diagnose problems
with the placenta. If the bleeding is
severe, the woman is given a blood
transfusion, and the baby is delivered
immediately by caesarean section.
anteriorRelating to the front of the
body. In human anatomy, the term is
synonymous with ventral.
anthelmintic drugsA group of drugs
that are used to eradicate worm infes-
tations. Possible side effects include
nausea, abdominal pain, rash, head-
ache, and dizziness.
anthracosisAn outdated term for coal
worker’s pneumoconiosis. Anthracosis is
a lung disease caused by the inhalation
of large amounts of coal dust over a
period of many years.ANORGASMIA ANTHRACOSISA