glomerulosclerosisScarring caused by
damage to the glomeruli (see glomerulus).
Mild glomerulosclerosis occurs normally
with age. Glomerulosclerosis may occur
in some severe types of glomeruloneph-
ritis. It is also sometimes associated
with diabetes mellitus, hypertension,
AIDS, or intravenous drug abuse.
glomerulusA filtering unit of the kidney
that consists of a cluster of capillaries
enclosed in a capsule and supplied with
blood from the renal artery. Each glom-
erulus is a part of a larger filtering unit
called a nephron. Filtered blood eventu-
ally leaves the kidney via the renal vein.
(See also glomerulonephritis.)glomus tumourA small, bluish swel-
ling in the skin, usually on a finger or
toe near or under the nail, which is ten-
der to touch and more painful if the
limb is hot or cold. The cause is over-
growth of the nerve structures that
normally control blood flow and tem-
perature in the skin. The tumours are
harmless but are surgically removed.
glossectomyRemoval of all or part of
the tongue. Glossectomy may be per-
formed to treat tongue cancer.
glossitisInflammation of the tongue.
The tongue feels sore and swollen and
looks red and smooth; adjacent parts of
the mouth may also be inflamed.GLOBULIN GLOSSITIS
G
usually mild and infrequent, but dizzi-
ness and drowsiness may occur. Rarely,
glipizide can cause an abnormal reac-
tion of the skin to sunlightand can
reduce blood sodium levels.
globulinAny of a group of proteins that
are insoluble in water but soluble in
dilute salt solutions. There are a number
of globlulins in the blood, including im-
munoglobulins(also called antibodies).
globus hystericusA condition in which
there is an uncomfortable feeling of a
“lump in the throat”. This lump is felt to
interfere with swallowing and breathing,
although there is no physical basis for
the condition. In severe cases, hyper-
ventilationand symptoms of a panic
attackensue. In most cases, the condi-
tion occurs most commonly in people
who are anxious or depressed. Treat-
ment is by reassurance, breath-control
training, or psychotherapy.
glomerulonephritisInflammation of
the glomeruli (see glomerulus), affecting
both kidneys. Damage to the glomeruli
hampers the removal of waste products,
salt, and water from the bloodstream,
which may cause serious complications.
Some types of glomerulonephritis are
caused by immune complexes (compon-
ents of the immune systemproduced in
response to infection) becoming trapped
in the glomeruli. The condition occurs
in some autoimmune disorders. Infec-
tious diseases such as malaria and
schistosomiasisare important causes of
glomerulonephritis in tropical countries.
Mild glomerulonephritis may produce
no symptoms. Some sufferers experience
a dull ache over the kidneys. The urine
may become bloodstained. Loss of pro-
tein into the urine may cause oedema
(seenephrotic syndrome). Hypertension
is a potentially serious complication.
Long-term glomerulonephritis is a com-
mon causeof chronic kidney failure.
Diagnosis involves kidney function tests,
urinalysis, and kidney biopsy. Treatment
depends on the cause and severity of
the disease. Children with nephrotic
syndrome usually respond to cortico-
steroid drugs. In adults, kidney failure
can sometimes be prevented or delayed
by drug treatment and dietary control to
reduce the work of the kidneys.
Glomerular
capsule
Capillaries
Renal
cortexGLOMERULUSUreterRenal veinGLOMERULUSKIDNEYRenal arteryRenal pelvis