PREMENSTRUAL TENSION
PRESSURE SORES
Theories for the cause of PMS include
hormonal changes and vitamin or min-
eral deficiencies, but none have been
confirmed. The most common emotional
symptoms are irritability, tension, depres-
sion, and fatigue. Physical symptoms
include breast tenderness, fluid reten-
tion, headache, backache, and lower
abdominal pain.
No single treatment has proved com-
pletely successful. Treatments to relieve
specific symptoms include
duretic drugs,
dietary changes, and relaxation tech-
niques. Pyridoxine (vitamin B
6
) or even-
ing primrose oil may help some women.
Oral contraceptives
can relieve symptoms
by suppressing the normal menstrual
cycle. Progesterone supplements are
widely used but not always effective.
premenstrual
tension
See
premen-
strual syndrome.
premolar
One of
8
permanent grinding
teeth,
2
in the upper and
2
in the lower
jaw on each side of the mouth, located
between the canines and molars. (See
also
permanent teeth; eruption of
teeth.)
prenatal
The
period
of
pregnancy
before childbirth.
prepuce
See
foreskin.
presbyacusis
The progressive loss of
hearing that occurs with age. Presbyacu-
sis is a form of sensorineural
deafness
,
which makes sounds less clear and tones
less audible. People with the condition
often find it difficult to understand
speech and cannot hear well when there
is background noise. Presbyacusis may
be exacerbated by exposure to high
noise
levels, diminished blood supply
to the inner ear due to
atherosclerosis
,
and damage to the inner ear from drugs
such as
aminoglycoside drugs. Hearing-
aids
help most people.
presbyopia
The progressive loss of the
power of adjusting the eye (see
accom-
modation
) for near vision. The focusing
power of the eyes weakens with age.
Presbyopia is usually noticed around
age 45 when the eyes cannot accommo-
date to read small print at a normal
distance. Reading
glasses
with convex
lenses are used to correct presbyopia.
prescribed diseases
A group of in-
dustrial diseases that give sufferers
legal entitlement to financial benefit. A
claimant has to have worked in an occu-
pation recognized to increase the risk of
developing a particular disease. Exam-
ples include conditions due to physical
agents (such as occupational
deafness
),
biological agents (for example,
anthrax
),
or chemical agents (such as
lead poison-
ing
);
pneumoconiosis
;
and
byssinosis
.
(See also
notifiable diseases
;
occupa-
tional disease and injury.)
prescription
An instruction written by
a doctor that directs a pharmacist to
dispense a particular drug in a specific
dose. A prescription details how often
the drug must be taken, how much is to
be dispensed, and other relevant facts.
prescription-only medicine
Drugs and
medicines that are not available over the
counter and can only be obtained by
prescription
. Prescription-only medicines
are those whose safe use is difficult to
ensure without medical supervision.
preservative
A substance that inhibits
growth of bacteria, yeasts, and moulds
and so protects foods from putrefying
and fermenting. Examples include sul-
phur dioxide, benzoic acid, salt, sugar,
and nitrites. (See also
food additives
.)
pressure points
Places on the body
where arteries lie near the surface and
pressure can be applied by hand to
limit severe arterial bleeding (in which
bright red blood is pumped out in regu-
lar spurts with the heartbeat). Major
pressure points of the body include the
brachial pressure point in the middle
part of the upper arm and the carotid
pressure point at the side of the neck,
below the jaw.
pressure sores
Ulcers that develop on
the skin of patients who are unconscious
or immobile. They are also known as
decubitus ulcers or bedsores. Common
sites include the shoulders, elbows,
lower back, hips, buttocks, ankles, and
heels. Pressure sores may develop fol-
lowing
stroke
or
spinal injuries
that
result in a loss of sensation.
Inconti-
nence
, if it results in constantly wet skin,
may also be a contributory factor. Pres-
sure sores start as red, painful areas that
become purple before the skin breaks
down. At this stage, the sores often
become infected and are very slow to
heal. Deep, chronic
ulcers
may require
P
463
previous page 461 BMA Illustrated Medical Dictionary read online next page 463 BMA Illustrated Medical Dictionary read online Home Toggle text on/off