due to emotion, conjunctival or corneal
irritation, or an obstruction to the chan-
nel that drains tears from the eye. (See
also lacrimal apparatus.)
water intoxicationA condition that is
caused by excessive water retention in
the brain. The principal symptoms are
headaches, dizziness, nausea, confu-
sion, and, in severe cases, seizures and
unconsciousness.
Various disorders can disrupt the
water balance in the body, leading to
accumulation of water in the tissues.
Examples include kidney failure, liver cir-
rhosis, severe heart failure, diseases of
the adrenal glands, and certain lung or
ovarian tumours producing a substance
similar to ADH(antidiuretic hormone).
Water intoxication is also seen in asso-
ciation with the use of Ecstasy(MDMA),
during which excessive amounts of
water are drunk. There is also a risk of
water intoxication after surgery, caused
by increased ADH production.
water on the brainA nonmedical
term for hydrocephalus.
water on the kneeA popular term for
accumulation of fluid within or around
the knee joint. The most common cause
is bursitis. (See also effusion, joint).
water retentionAccumulation of fluid
in body tissues (see oedema).
water tabletsA nonmedical term for
diuretic drugs.
wax bathA type of heat treatmentin
which hot liquid wax is applied to a part
of the body to relieve pain and stiffness
in inflamed or injured joints. Wax baths
may be used to treat the hands of peo-
ple with rheumatoid arthritis.
weaknessA term used to describe a lack
of vigour or strength. This is a common
symptom of a wide range of conditions,
including anaemia, emotional problems,
and various disorders affecting the heart,
nervous system, bones, joints, and mus-
cles. When associated with emotional
disorders, weakness may represent a lack
of desire or ambition, rather than loss
of muscle strength.
More specifically, the term describes
loss of power in particular muscle
groups, which may be accompanied by
muscle wasting and loss of sensation.
(See also paralysis.)
wealA raised bump on the skin that
is paler than the adjacent tissue and
which may be surrounded by an area of
red inflammation. Weals are character-
istic of urticaria.
weaningThe gradual substitution of
solid foods for milk or milk formula in
an infant’s diet (see feeding, infant).
webbingA flap of skin, such as might
occur between adjacent fingers or toes.
Webbing is a common congenital abnor-
malitythat often runs in families and
which may affect 2 or more digits. Mild
webbing is completely harmless, but sur-
gical correction may be performed for
cosmetic reasons. In severe cases, adja-
cent digits may be completely fused (see
syndactyly). Webbing of the neck is a
feature of Turner’s syndrome.
Wegener’s granulomatosisA rare
disorder in which granulomas(nodular
collections of abnormal cells), associated
with areas of chronic tissue inflamma-
tion due to vasculitis,develop in the
nasal passages, lungs, and kidneys. It is
thought that the condition is an auto-
immune disorder(in which the body’s
natural defences attack its own tissues).
Principal symptoms include a bloody
nasal discharge, coughing (which some-
times produces bloodstained sputum),
breathing difficulty, chest pain, and
blood in the urine. There may also be
loss of appetite, weight loss, weakness,
fatigue, and joint pains.
Treatment is with immunosuppressant
drugs, such as cyclophosphamideor aza-
thioprine, combined with corticosteroids
to alleviate symptoms and attempt to
bring about a remission. With prompt
treatment, most people recover com-
pletely within about a year, although
kidney failureoccasionally develops.
Without treatment, complications may
occur, including perforation of the nasal
septum, causing deformity of the nose;
inflammation of the eyes; a rash, nod-
ules, or ulcers on the skin; and damage
to the heart muscle, which may be fatal.
weightThe heaviness of a person or
object. In children, weight is routinely
used as an index of growth. In healthy
adults, weight remains more or less sta-
ble as dietary energy intake matches
energy expenditure (see metabolism).WATER INTOXICATION WEIGHT
W