rabies - a widespread, viral infection of warm-blooded animals caused by a virus in the Rhabdoviridae family Rabies attacks the nervous system and, once symptoms develop, is 100 percent fatal in animals.
radial keratotomy - a surgical procedure in which incisions are made into the epithelium of the cornea to correct refractive errors.
radiation - use of high-energy radiation from x-rays, neutrons, and other sources to kill cancer cells and shrink tumors.
radiation colitis - damage to the colon from radiation therapy.
radiation enteritis - damage to the small intestine from radiation therapy.
radiation therapy (Also called radiotherapy.) - treatment with high-energy rays (such as x-rays or gamma rays) to kill cancer cells; may be by external radiation or by internal radiation from radioactive materials placed directly in or near the tumor.
radical mastectomy - surgery to remove the entire breast (including the nipple, areola, and overlying skin), the lymph nodes under the arm, also called the axillary lymph glands, and the chest muscles.
radical prostatectomy - surgery to remove the prostate along with the two seminal vesicle glands attached to the prostate.
radical retropubic prostatectomy - an operation to remove the entire prostate gland and seminal vesicles through the lower abdomen.
radioisotope - a radioactive material injected into the body so that a nuclear scanner can make pictures.
radioisotope scan - a procedure that uses radioactive substances introduced into the body to create an image.
radioisotopes - materials that produce radiation.
radiologist - a physician specializing in the medical field of radiology.
radionuclide bone scan - a nuclear imaging technique that uses a very small amount of radioactive material, which is injected into the patient's bloodstream to be detected by a scanner. This test shows blood flow to the bone and cell activity within the bone.
radionuclide scan - an imaging scan in which a small amount of radioactive substance is injected into the vein. A machine measures levels of radioactivity in certain organs, thereby detecting any abnormal areas or tumors.
radionuclide ventriculography - a diagnostic procedure used to determine the shape and size of the heart's chambers.
radiopharmaceutical (Also called a tracer or radionuclide.) - basic radioactively-tagged compound necessary to produce a nuclear medicine image.
radius - the shorter of the two bones of the forearm.
radon - a colorless, naturally-occurring, radioactive, inert gas formed by radioactive decay of radium atoms in soil or rocks.
Rancho scales - Levels of a patient's response to external stimuli and the environment following a brain injury.
range of motion - measurement of the extent to which a joint can go through all of its normal spectrum of movements.
rape - forced or manipulated nonconsensual sexual contact, including vaginal or anal intercourse, oral sex, or penetration with an object.
RAST (RadioAllergoSorbent Test, a trademark of Pharmacia Diagnostics) - a laboratory test used to detect IgE antibodies to specific allergens. A RAST requires a blood sample, which is sent to a medical laboratory where tests are done with specific foods to determine whether the patient has IgE antibodies to that food.
reactive arthritis (Also called Reiter's syndrome.) - a type of arthritis that occurs as a reaction to an infection.
recommended dietary allowance (RDA) - recommendations for daily intake of specific nutrients for groups of healthy individuals set by the Food and Nutrition Board of the National Research Council of the National Academy of Science.
reconstructive plastic surgery - one type of plastic surgery that is performed on abnormal structures of the body that may be caused by trauma, infection, developmental abnormalities, congenital defects, disease, and/or tumors. This type of surgery is usually performed to improve function, but may also be performed to approximate a normal appearance.
rectal manometry - test that uses a thin tube and balloon to measure pressure and movements of the rectal and anal sphincter muscles.
rectal prolapse - condition in which the rectum slips so that it protrudes from the anus.
rectal ultrasound - a test in which a probe is inserted in the rectum and directs sound waves at the prostate. The patterns of the sound waves form an image of the prostate gland on a screen.
rectocele - condition in which weakening of the lower vaginal wall causes the rectum to bulge into the vagina.
rectum - lower end of the large intestine, leading to the anus.
recur - to occur again; reappearance of cancer cells at the same site or in another location.
red blood cells (Also called RBCs or erythrocytes.) - blood cells that transport oxygen to all the tissues in the body.
reflux (Also called regurgitation.) - condition that occurs when gastric juices or small amounts of food from the stomach flow back into the esophagus and mouth.
reflux esophagitis - irritation of the esophagus because stomach contents flow back into the esophagus.
refractive error - the degree to which light reaches the back of the eye - myopia, hyperopia, astigmatism.
regional anesthetic - an anesthetic used to numb a portion of the body.
regurgitation - backward flow of blood caused by a defective heart valve.
rehabilitation - the process of helping a person achieve the highest level of function, independence, and quality of life possible. From the Latin "habilitas," which means "to make able."
renal - pertains to kidneys.
renal angiography (Also called renal arteriography.) - a series of x-rays of the renal blood vessels with the injection of a contrast dye into a catheter, which is placed into the blood vessels of the kidney; to detect any signs of blockage or abnormalities affecting the blood supply to the kidneys.
renal ultrasound - a non-invasive test in which a transducer is passed over the kidney producing sound waves which bounce off of the kidney, transmitting a picture of the organ on a video screen. The test is used to determine the size and shape of the kidney, and to detect a mass, kidney stone, cyst, or other obstruction or abnormalities.
required surgery - an operation which is necessary to continue quality of life. Required surgery may not have to be done immediately, like emergency surgery.
residential care facility (RCF) - an out-of-home care option for elderly persons who are no longer able to live alone and independently, but do not require skilled nursing care. RCFs typically provide assistance with personal hygiene, grooming, and other activities of daily living, as well as recreational and social services.
respiration - gas exchange from air to the blood and from the blood to the body cells.
respiratory diphtheria - when a person is infected with diphtheria, the bacterium usually multiplies in the throat, leading to the respiratory version of diphtheria. A membrane may form over the throat and tonsils, causing a sore throat. Other common symptoms of respiratory diphtheria may include: breathing difficulty, a husky voice, enlarged lymph glands, and an increased heart rate.
respiratory system - the group of organs responsible for carrying oxygen from the air to the bloodstream, and for expelling carbon dioxide.
resting tremor - a tremor of a limb that increases when the limb is at rest.
retching - dry vomiting.
retina - the light-sensitive nerve layer that lines the back of the eye. The retina sense light and creates impulses that are sent through the optic nerve to the brain.
retinal detachment - separation of the retina from the epithelium layer and from blood supply.
retinopathy - diabetic eye disease.
retrolisthesis - posterior slippage of one vertebra onto another.
retropulsion - the tendency to step backwards if bumped from the front or upon initiating walking; usually seen in patients who tend to lean backwards because of problems with balance.
Reye syndrome - A potentially fatal disease that causes severe problems with the brain and other organs. Although the exact cause of the disease is not known, there has been an association with giving aspirin to children and developing the disease. It is now advised not to give aspirin to children during illnesses, unless prescribed by your child's physician.
rheumatic fever - a childhood disease that may damage the heart valves or the outer lining of the heart.
rheumatoid arthritis - an inflammatory disease that involves the lining of the joint (synovium). The inflammation often affects the joints of the hands and the feet and tends to occur equally on both sides of the body.
rheumatoid factor - special kind of antibody often found in people with rheumatoid arthritis.
rhinitis - an inflammation of the mucous membrane that lines the nose, often due to an allergy to pollen, dust, or other airborne substances, which causes sneezing, itching, runny nose, and nasal congestion.
rhinoplasty - the surgical repair of a defect of the nose, including reshaping or resizing the nose. Rhinoplasty may be performed to change the size of the nose, change the shape of the nose, narrow the nostrils, and/or change the angle between the nose and lips. Rhinoplasty involves the resculpting of the bone and cartilage.
rhytidectomy (Also called facelift.) - a surgical procedure that involves the removal of excess facial fat, the tightening of facial muscles, and the stretching of facial skin - to approximate a smoother, firmer appearance. The procedure takes place on either the face, neck, or both.
R.I.C.E. (Rest, Ice, Compression, and Elevation) - treatment plan for acute injury to prevent inflammatory processes from becoming uncontrolled and to speed up the recovery process by eliminating swelling; acute injury management.
rigidity - increased resistance to the passive movement of a limb.
ringworm - a fungal skin infection characterized by ring-shaped, red, scaly, or blistery patches.
risk factor - activity or factor that may increase the chance of developing a disease.
rooting - when a newborn turns his/her head toward touch near the mouth.
rosacea - a common skin condition characterized by redness, pimples, and broken blood vessels.
rotator cuff - muscles and tendons that form a cuff over the shoulder joint and attach the scapula to the bone in the upper arm (humerus); major function is to control and produce rotation of the shoulder.
round window - membrane separating the middle ear and inner ear.
rubella (Also called German measles.) - an acute viral infection that causes a mild illness in children and slightly more severe illness in adults. The disease is spread person-to-person through airborne particles and takes two to three weeks to incubate.
rupture - break or tear in any organ or soft tissue.