Medical Dictionary: Q and R

quick relievers: Medications that quickly open the bronchial tubes by relaxing the muscles surrounding these airways. Quick relievers can be used as needed for relief of asthmatic symptoms rather than on a regular schedule.

quiet sleep: All sleep except REM sleep. In the quiet phase of sleep, thinking and most physiological activities slow, but movement still occurs. Also called non-REM sleep.

radial tunnel syndrome: a condition in which the radial nerve is compressed at the elbow.

radiation therapy: Treatment with high-energy rays (from x-rays or other sources) designed to control disease and destroy cancer cells.

radical prostatectomy: A surgical procedure in which the entire prostate is removed.

radiculopathy: See cervical radiculopathy.

radioactive iodine: A radioactive form of iodine that can be used as a tracer during a radioactive iodine uptake test or a radioactive thyroid scan. Much larger amounts are used in the treatment of hyperthyroidism.

radiofrequency: A technique for tightening lax skin on the face, using an electromagnetic current to penetrate deep within the skin’s dermis.

randomized: A feature of many clinical trials in which participants are randomly assigned to a group to be tested or a control group.

rapid eye movement (REM) sleep: A period of intense brain activity during sleep, often associated with dreams; named for the rapid eye movements that occur during this time. Also called dreaming sleep.

RAST (radioallergosorbent test): A blood test used for identifying allergens.

Raynaud’s syndrome: a condition in which the blood vessels in the fingers and other extremities narrow in response to cold or stress, causing them to turn white or blue.

reactive arthritis: Joint problems triggered by bacterial or viral infection elsewhere in the body.

recombinant tissue plasminogen activator (tPA): A thrombolytic drug made using recombinant DNA technology; it can sometimes dissolve blood clots that cause ischemic strokes.

recommended dietary allowance (RDA): The average daily amount of a micronutrient that will meet the nutritional needs of almost all (97%–98%) healthy people at specific stages of their lives.

rectocele: A weakening of the vaginal wall that allows the rectum to bulge into the vagina.

rectum: The last 12 centimeters of the colon, through which waste is eliminated from the body.

rehabilitative driving specialist: A professional trained to evaluate driving skills and, when appropriate, suggest equipment and adaptations to make driving safer for people with certain limitations.

relaxation response: A term coined by Dr. Herbert Benson to describe the physical effects of meditation and certain other techniques that are opposite to those of the stress response. Effects include marked drops in oxygen consumption, carbon dioxide expiration, heartbeat, and respiration, as well as stabilization or lowering of blood pressure.

remodeling: The body’s mechanism for systematically removing old bone tissue and replacing it with new bone to preserve the strength of the skeleton.

renal artery stenosis: Narrowing of an artery that supplies blood to the kidney.

renal: Having to do with the kidney.

renin: An enzyme released by the kidney that stimulates production of angiotensin.

resectoscope: An instrument that permits a surgeon to view the prostate during transurethral resection.

resistant hypertension: Blood pressure that remains persistently elevated despite drug therapy and lifestyle changes.

resorption: The removal of bone tissue — both protein and minerals — by osteoclasts.

restenosis: Renarrowing of a blood vessel that has been widened (with or without stents) during angioplasty.

resting energy expenditure: The rate at which you burn calories while at rest. Resting energy expenditure accounts for 60%–75% of daily energy expenditure.

restless legs syndrome (RLS): Achy or unpleasant feelings in the legs associated with a need to move. Most prominent at night, making it hard to fall asleep or stay asleep.

retina: The innermost layer of the eye, consisting of specialized cells and lining nearly three-quarters of the back of the eye; it converts light energy to electrical energy and sends visual images to the brain via the optic nerve.

retrieval: The act of recalling previously learned information; it involves the reactivation of particular nerve-cell pathways that encoded a given piece of information.

retrograde ejaculation: An adverse effect of prostate surgery and some medications that causes semen to flow back into the bladder rather than out through the penis.

rheumatic disease: Any one of over 100 disorders that cause inflammation in connective tissues.

rheumatoid arthritis: An inflammatory autoimmune disease that typically attacks the connective tissue of the joints, causing them to become painful, inflamed, and sometimes deformed.

rheumatoid factor: An antibody found in about 85% of people with rheumatoid arthritis; also appears in other diseases and sometimes in healthy people.

rheumatology: The branch of medicine devoted to the study and treatment of connective tissue diseases.

rhinoplasty (nose reshaping): Reshaping the cartilage and bone of the nose to achieve the desired profile.

rhytidectomy (facelift): A surgical procedure that involves removing excess skin and tightening the underlying muscle to correct sagging around the jaws, jowls, and neck. Does not include work on the eyes or forehead.

Rinne test: A simple hearing test that uses a tuning fork to determine what type of hearing loss a person has.

rods: Light-sensitive cells in the retina that respond best in darkness and dim light.

rosacea: A skin condition that enlarges vessels, causing redness of the nose and other parts of the face.

ruptured disk: See herniated disk.