| Rabies |
an
infectious viral disease primarily affecting animals; can
be transmitted to humans through an infected animal's bite;
if untreated, can result in paralysis and death |
| Radial
keratotomy |
a
surgical procedure for correcting nearsightedness in which
tiny cuts are made in the cornea to change its shape and focusing
properties |
| Radiation |
a
variety of types of energy, such as X-rays and ultraviolet
|
| Radiation
therapy |
treatment
of a disease, such as cancer, using forms of radioactivity
that damage or destroy abnormal cells |
| Radical
surgery |
treatment
of disease by surgically removing all tissue that is or may
be affected |
| Radiculopathy |
any
disease of the nerve roots; can be caused by disk prolapse,
arthritis, and other problems |
| Radioallergosorbent
test |
a
blood test performed to help determine the cause of an allergy
by detecting the presence of antibodies to various allergens |
| Radiography |
the
formation of images of the inside of the body using radiation
projected through the body and onto film; a radiograph is
also called an X-ray |
| Radionuclide
scanning |
an
imaging technique in which a radioactive substance is introduced
into the body and its emitted radiation is detected; specific
organs can be studied according to the amount of the radioactive
substance that they absorb |
| Radius |
one
of the two long bones of the forearm, located on the thumb
side of the arm |
| Radon |
a
colorless, odorless, tasteless radioactive gas that is produced
by materials in soil, rocks, and building materials; suspected
of causing cancer |
| Rales |
abnormal
crackling or bubbling sounds heard in the lungs during breathing |
| Rash |
an
area of inflammation or a group of spots on the skin |
| Raynaud's
disease |
a
condition in which the fingers and toes become pale when exposed
to cold or emotional stress, owing to sudden narrowing of
the arteries that supply them with blood |
| Receptor |
a
nerve cell that responds to a stimulus and produces a nerve
impulse; also refers to the area on the surface of a cell
that a chemical must bind to in order to have its effect |
| Recessive
gene |
a
gene that does not produce its effect when it occurs with
a dominant gene, but produces its effect only when there are
two copies of it |
| Reconstructive
surgery |
surgery
to rebuild part of the body that has been damaged or defective
from birth |
| Rectal
prolapse |
bulging
of the lining of the rectum through the anus, usually due
to straining during a bowel movement |
| Rectum |
a
short tube located at the end of the large intestine, which
connects the intestine to the anus |
| Red
blood cell |
a
doughnut-shaped blood cell that carries oxygen from the lungs
to body tissues |
| Reduction
of fracture |
the
realignment of the broken ends of a bone |
| Referred
pain |
pain
felt in a part of the body remote from the site where pain
originates |
| Reflex |
an
automatic, involuntary response of the nervous system to a
stimulus |
| Reflux
esophagitis |
the
backflow of gastric acid from the stomach to the lower esophagus,
owing to a defect in the valve that separates them |
| Regurgitation |
the
backflow of fluid; can refer to food and drink flowing back
up from the stomach into the mouth or blood flowing back into
the heart through a defective heart valve |
| Rehabilitation |
treatment
for an injury or illness aimed at restoring physical abilities
|
| Rehydration |
treatment
for dehydration (an abnormally low level of water in the body)
in which levels are restored by taking fluids containing water,
salt, and glucose by mouth or, if severe, through a vein |
| Reiter's
syndrome |
a
disorder characterized by inflammation of the joints, urethra,
and sometimes the conjunctiva |
| Relapse |
the
return of a disease or symptom after it had disappeared |
| Remission |
the
temporary disappearance of a disease or its symptoms, either
partially or completely; also refers to the time period in
which this occurs |
| REM
sleep |
rapid
eye movement sleep; the stage of sleep in which dreaming occurs |
| Renal
cell carcinoma |
the
most common type of kidney cancer |
| Renal
colic |
severe
pain on one side of the lower back, usually as a result of
a kidney stone |
| Renal
tubular acidosis |
inability
of the kidneys to remove sufficient amounts of acid from the
body, making the blood more acidic than normal |
| Renin |
an
enzyme that plays a role in increasing a low blood pressure
|
| Repetitive
strain injury |
an
injury that occurs when the same movement is repeated continuously |
| Reproductive
system |
the
organs and structures that allow men and women to have sexual
intercourse and produce children |
| Resection |
partial
or complete surgical removal of a diseased organ or structure |
| Respiration |
the
process by which oxygen is taken in and used by tissues in
the body and carbon dioxide is released |
| Respirator |
another
term for a ventilator |
| Respiratory
arrest |
a
condition in which a person suddenly stops breathing |
| Respiratory
distress syndrome |
a
condition experienced after an illness or injury damages the
lungs, causing severe breathing difficulty and resulting in
a life-threatening lack of oxygen in the blood |
| Respiratory
failure |
the
failure of the body to exchange gases properly, which leads
to a buildup of carbon dioxide and a lack of oxygen in the
blood |
| Respiratory
system |
the
organs that carry out the process of respiration |
| Resting
pulse |
the
pulse rate when a person is not experiencing any physical
activity or mental stress |
| Reticulocyte |
an
immature red blood cell |
| Retina |
a
membrane lining the inside of the back of the eye that contains
light-sensitive nerve cells that convert focused light into
nerve impulses, making vision possible |
| Retinal
artery occlusion |
obstruction
of an artery that supplies blood to the retina, resulting
in some degree of temporary or permanent blindness |
| Retinitis
pigmentosa |
gradual
loss of the field of vision, owing to a degeneration of the
light-sensitive nerve cells of the retina |
| Retinoblastoma |
a
hereditary, cancerous tumor of the retina affecting infants
and children |
| Retinoid |
a
substance resembling vitamin A that is used to treat skin
conditions such as acne and has been reported to reduce skin
wrinkling |
| Retinopathy |
any
disease or disorder of the retina; usually refers to damage
to the retina caused by high blood pressure or diabetes mellitus |
| Retinoscopy |
a
method of determining focusing errors of the eye in which
light is shined through the pupil and the reflected beam is
measured |
| Retroviruses |
a
group of viruses that are made up of RNA instead of DNA, including
HIV and the virus that causes T-cell leukemia |
| Reye's
syndrome |
a
rare disorder mainly affecting those under the age of 15 that
is characterized by brain and liver damage following a viral
infection such as chickenpox or the flu; may be linked to
taking aspirin to treat a viral infection |
| Rh
blood group |
a
blood group classifying whether the substances called Rhesus
(Rh) factors are present on the surface of red blood cells;
the "positive" or "negative" designation in blood classification
(for example, "O negative") |
| Rheumatic
fever |
a
disorder that follows a throat infection by the streptococcus
bacteria and causes inflammation in body tissues |
| Rheumatoid
arthritis |
a
condition in which joints in the body become inflamed, stiff,
painful, and sometimes deformed because of the body's own
immune system attacking the tissues |
| Rheumatoid
factors |
antibodies
that are present in about 80% of people with rheumatoid arthritis;
their detection through blood testing can help to diagnose
the disorder |
| Rh
immunoglobulin |
a
substance used to prevent a woman who is Rh incompatible with
her fetus from becoming Rh sensitized |
| Rh
incompatibility |
a
condition in which a pregnant woman's Rh factor does not match
that of the fetus; can lead to the production of antibodies
by the mother that destroy the fetus' red blood cells |
| Rhinitis |
inflammation
of the mucous membrane lining the nose, which can cause sneezing,
runny nose, congestion, and pain; when caused by substances
in the air, it is called allergic rhinitis or hay fever |
| Rhinophyma |
a
bulb-shaped deformity and redness of the nose as a result
of severe rosacea |
| Rhinoplasty |
surgery
that changes the structure of the nose, either to improve
appearance or to correct a deformity or injury |
| Rh
sensitized |
a
condition in which a woman who has a negative Rh factor develops
permanent antibodies against Rh-positive blood as a result
of exposure to the blood of her fetus; can cause fetal hemolysis
in subsequent pregnancies |
| Rhythm
method |
a
method of preventing pregnancy in which a couple does not
have sexual intercourse during the days of the menstrual cycle
during which fertilization can occur |
| Riboflavin |
a
vitamin belonging to the vitamin B complex that is important
in many processes in the body and helps to maintain healthy
skin |
| Rickets |
a
childhood disease in which bones lack calcium and are deformed
as a result of vitamin D deficiency (vitamin D helps the body
absorb calcium) |
| Rigor
mortis |
the
stiffness that occurs in the body after death |
| Ringworm |
a
skin infection caused by a fungus that spreads out in an even
circle, characterized by ring-like, scaly patches of red skin |
| Rinne's
test |
a
test that uses a tuning fork to diagnose hearing loss resulting
from poor conduction of sound from the outer to the inner
ear |
| RNA |
ribonucleic
acid, which helps to decode and process the information contained
in DNA |
| Rocky
mountain spotted fever |
a
rare disease transmitted to humans through the bites of ticks;
characterized by small pink spots on the wrists and ankles
that spread to other parts of the body, become larger, and
bleed |
| Rosacea |
a
skin disorder that is characterized by patches of red skin
on the nose and cheeks and acne-like bumps; most commonly
occurs in middle-aged women |
| Roseola
infantum |
a
common disease in young children characterized by a sudden
fever and rash |
| Rotator
cuff |
a
structure made up of four muscle tendons that reinforces the
shoulder joint |
| Roundworm |
a
group of worms that includes many of the major human parasites |
| Rubella |
a
mild viral infection (also known as German measles) that produces
a rash and fever; dangerous when it infects a woman during
the early stages of pregnancy, when it can spread causing
birth defects in the fetus |
| Rubeola |
another
term for measles |
| Rupture |
a
tear or break in an organ or tissue |
