Medications

Regulatory region: A region of a chromosome that controls gene expression. In terms of DNA, it is a regulatory sequence.Last Editorial Review: 4/14/2001 Chromosome: A visible carrier of the genetic information. The 3 billion bp (base pairs) i...

Regulatory gene - Medical

Regulatory gene: A gene that regulates the expression of other genes. A regulatory gene is a nosy gene whose prime preoccupation is to horn in on other genes and control the rate at which they make products.Last Editorial Review: 4/27/2011 5:27:15 P...

Regress - Medical

Regress: To return or go back, particularly to return to a pattern of behavior or level of skill characteristic of a younger age. For example, if a three-year-old child begins to regress by losing the ability to control his bowels or speak, tha...

Registry, tumor - Medical

Registry, tumor: See: Tumor registry. And, for more information, see: Cancer registry.Last Editorial Review: 6/13/2004 Tumor registry: Recorded information about the status of patients with tumors. Although a registry was originally the place (li...

Registry - Medical

Registry: Although a registry was originally the place (like Registry House in Edinburgh) where information was collected (in registers), the word registry has also come to mean the collection itself. A registry is usually organized so the data can ...

Regional lymphadenitis - Medical

Regional lymphadenitis: Cat scratch disease, a mild flu-like infection, with swollen lymph nodes (lymphadenitis) and mild fever of short duration, due to cat scratches, especially from kittens. There is usually a little bump (a papule) which may be ...

Regional enteritis - Medical

Regional enteritis: Crohn's disease, a chronic inflammatory disease of the intestine primarily in the small and large intestines but which can occur anywhere in the digestive system between the mouth and the anus. Named after Burrill Crohn who de...

Region, regulatory - Medical

Region, regulatory: A region of a chromosome that controls gene expression. In terms of DNA, it is a regulatory sequence.Last Editorial Review: 4/14/2001 Chromosome: A visible carrier of the genetic information. The 3 billion bp (base pairs) ...

Regimen - Medical

Regimen: With the accent on the first syllable (reg as in Reggie Jackson), a regimen is a plan, a regulated course such as a diet, exercise or treatment, designed to give a good result. A low-salt diet is a regimen.Last Editorial Review: 4/27/2011 5...

Regenerate - Medical

Regenerate: To reproduce or renew something lost. For example, after an injury, the liver has the capacity to regenerate.Last Editorial Review: 4/27/2011 5:27:15 PM...

Refsum disease - Medical

Refsum disease: A genetic disorder affecting the metabolism of the fatty acid phytanic acid. When phytanic acid accumulates, it causes a number of progressive problems, including inflammation of numerous nerves (polyneuritis), diminishing visio...

$Refractory anemia - Medical$

Refractory anemia - Medical

Refractory anemia: Anemia (a shortage of red blood cells) unresponsive to treatment.Last Editorial Review: 4/27/2011 5:27:15 PM Medical Author: Siamak T. Nabili, MD, MPH ...

$Refractory - Medical$

Refractory - Medical

Refractory: Not yielding (at least not yielding readily) to treatment.Last Editorial Review: 4/27/2011 5:27:15 PM...

$Refraction test - Medical$

Refraction test - Medical

Refraction test: Also termed vision test, the refraction test is an examination that tests an individual's ability to see an object at a specific distance. The test is performed by an optometrist or ophthalmologist in the doctor's office. The ref...

$Refraction - Medical$

Refraction - Medical

Refraction: In ophthalmology, the bending of light that takes place within the human eye. Refractive errors include nearsightedness (myopia), farsightedness (hyperopia), and astigmatism. Lenses can be used to control the amount of refraction...

$Refract - Medical$

Refract - Medical

Refract: In ophthalmology, to determine the bending of light that takes place within the human eye. Refractive errors include nearsightedness (myopia), farsightedness (hyperopia), and astigmatism. Lenses can be used to control the amount of refracti...

Reflux, esophageal - Medical

Reflux, esophageal: A condition wherein stomach contents regurgitate or back up (reflux) into the esophagus (a long cylindrical tube that transports food from the mouth to the stomach). The food in the stomach is partially digested by stomach acid...

Reflux surgery (fundoplication) - Medical

Reflux surgery (fundoplication): A surgical technique that strengthens the barrier to acid reflux when the lower esophageal sphincter does not work normally and there is gastro-esophageal reflux. Fundoplication has been the standard surgical method ...

Reflux laryngitis - Medical

Reflux laryngitis: Inflammation of the voice box (the larynx) caused by stomach acid backing up into the esophagus. Reflux laryngitis is associated with chronic hoarseness and symptoms of esophageal irritation such as heartburn. Reflux is cau...

Reflux disease, gastroesophageal (GERD) - Medical

Reflux disease, gastroesophageal (GERD): The stomach contents regurgitate and back up (reflux) into the esophagus The food in the stomach is partially digested by stomach acid and enzymes. Normally, the partially digested acid content in the st...

Reflux - Medical

Reflux: The term used when liquid backs up into the esophagus from the stomach.Last Editorial Review: 4/27/2011 5:27:15 PM...

Reflex, quadriceps - Medical

Reflex, quadriceps: See: Knee jerk. Last Editorial Review: 7/17/2004 Knee jerk: The reflex tested by tapping just below the knee causing the lower leg to suddenly jerk forward. What is tapped to elicit this reaction is the patellar tendon, ...

Reflex, pressor - Medical

Reflex, pressor: A pressor reflex is a neurological (nerve) reflex that constricts arterioles (small blood vessels) and thereby increases the blood pressure. "Pressor" refers to raising the blood pressure. The word comes from the French "presser" m...

Reflex, photic sneeze - Medical

Reflex, photic sneeze: A disorder characterized by nearly uncontrollable paroxysms of sneezing provoked in a reflex fashion by the sudden exposure of a dark-adapted subject to intensely bright light, usually to brilliant sunlight. The number of succe...

Reflex, patellar tendon - Medical

Reflex, patellar tendon: See: Knee jerk.Last Editorial Review: 7/17/2004 Knee jerk: The reflex tested by tapping just below the knee causing the lower leg to suddenly jerk forward. What is tapped to elicit this reaction is the patellar tendon, the...

Reflex, patellar - Medical

Reflex, patellar: See: Knee jerk.Last Editorial Review: 7/17/2004 Knee jerk: The reflex tested by tapping just below the knee causing the lower leg to suddenly jerk forward. What is tapped to elicit this reaction is the patellar tendon, the tendon...

Reflex, let down - Medical

Reflex, let down: The let down reflex of the mother is an involuntary reflex during breastfeeding which causes the milk to flow freely.Last Editorial Review: 3/26/1998 2:28:00 PM...

Reflex, Babinski - Medical

Reflex, Babinski: An important neurologic test based, believe it or not, upon what the big toe does when the sole of the foot is stimulated. If the big toe goes up, that may mean trouble. The Babinski reflex is obtained by stimulating the exter...

Reflex sympathetic dystrophy syndrome (RSDS) - Medical

Reflex sympathetic dystrophy syndrome (RSDS): RSDS is a condition that features a group of typical symptoms, including pain (often "burning" type), tenderness, and swelling of an extremity associated with varying degrees of sweating, wa...

Reflex sympathetic dystrophy (RSD) - Medical

Reflex sympathetic dystrophy (RSD): A condition characterized by diffuse pain, swelling and limitation of movement that follows an injury such as a fracture in an arm or leg, The symptoms are way out of proportion to the injury and may linger long af...