Webster's New World Medical Dictionary

rat-flea typhus
See 
typhus, murine.
rattlesnake bite
A poisonous bite from a mem-
ber of the pit viper family. All rattlesnakes are ven-
omous and secrete poisonous venom, and they are
the main culprit in deaths from snakebites in the US.
Emergency treatment is essential: With proper care,
rattlesnake bites are rarely fatal. The affected body
part should be kept immobile and below the level of
the heart, and the bite victim should be taken to the
nearest hospital. A tourniquet or bandage should
not be used, and no one should attempt to suction
out the wound by mouth. Treatment includes use of
antivenom and care for the puncture wound itself
and any symptoms that emerge, such as respiratory
distress. See also 
snakebite.
Raynaud’s disease
A condition that results in
discoloration of the skin on the fingers and/or toes
when a person is exposed to changes in tempera-
ture or to emotional events. Raynaud’s disease, also
known as primary Raynaud’s phenomenon, can
accompany other diseases; when it does, it is called
Raynaud’s phenomenon or secondary Raynaud’s
phenomenon. The skin discoloration occurs
because an abnormal spasm of the blood vessels
causes a diminished blood supply. Initially, the dig-
its involved turn white because of diminished blood
supply, and then they turn blue because of pro-
longed lack of oxygen. Finally, the blood vessels
reopen, causing flushing that turns the digits red.
Raynaud’s phenomenon
A condition that
results in discoloration of fingers and/or toes when
a person is exposed to changes in temperature or
emotional events and that occurs with a number of
conditions, including rheumatic diseases such as
scleroderma, rheumatoid arthritis, and systemic
lupus erythematosus; hormone imbalance, includ-
ing hypothyroidism and carcinoid imbalances;
trauma, such as from frostbite or the use of vibrat-
ing tools; medications, particularly propranolol
(brand name: Inderal), estrogens, nicotine, and
bleomycin; and, uncommonly, cancer. When the
discoloration occurs alone, it is called Raynaud’s
disease. See also 
Raynaud’s disease.
reabsorption
Being absorbed again. For exam-
ple, the kidney selectively reabsorbs substances it
has already secreted into the renal tubules, such as
glucose, protein, and sodium. These reabsorbed
substances are returned to the blood.