Medical dictionary

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Radiography: X-ray.
Radiological: X-ray-related.
Radiology: the use of x-rays in the diagnosis of a disease.
Radiotherapy: the use of x-rays and other forms of radiation in treatment. It kills cancer cells in the area of the body being treated and is therefore effective treatment for localised disease.
Rapid Eye Movement (REM): a state of sleep that recurs cyclically several times during a normal period of sleep and that is characterized by increased neuronal activity of the forebrain and midbrain, by depressed muscle tone, and esp. in humans by dreaming, rapid eye movements, and vascular congestion of the sex organs -- called also paradoxical sleep, rapid eye movement sleep.
Raynaud's phenomenon: spasm of arterioles, usually in the digits (and occasionally other parts such as the nose and tongue) with intermittent pallor or cyanosis of the skin.
Reabsorption: absorbing again.
Reactive arthritis: one of the more common forms of arthritis. Can affect tendons and their tissues as well as the joints. It can also be referred to as Reiter's syndrome or Reiter's disease and is one of a group of illnesses often classed under the heading of 'sero-negative arthritis' or 'spondarthritis'. It is quite distinct from rheumatoid arthritis and osteoarthritis. The usual causes are - sexually transmitted infection, acute infectious diarrhoea or food poisoning.
Reagent: reactive substance.
Receptor: specific proteins usually located on the surface of a cell that bind with antigens, antibodies and chemical messengers.
Recessive: a form of inheritance where a genetic defect causes little or no outward effect unless it is present in both of a pair of genes and has therefore been inherited from both parents. If a person has inherited one altered gene and one normal gene he or she will not be affected but will be a gene carrier. If two carriers of the same altered gene have children, in each pregnancy there is a 25 per cent chance that the child will inherit two copies of the altered gene and will be affected.
Recidivist: person who lapses back into old habits.
Recombinant: a term used to describe drugs which have been produced using the techniques of genetic engineering. The products are exact equivalents of compounds produced naturally by the body.
Rectal prolapse: a condition in which the rectum protrudes from the anus.
Rectum: the terminal section of the large intestine, including the anus.
Red blood cells: the cells of the blood which contain the red pigment haemoglobin and carry oxygen to all the tissues of the body.
Reed-sternberg cell: a distinctive abnormal cell seen in hodgkin's disease.
Reflexes: movements that the body makes automatically in response to a specific cue.
Reflexology: massage the pressure points in the hands and feet which correspond to different parts of the body providing overall relaxation and restoring balance.
Reflux: return flow, usually of acid.
Reflux oesophagitis: irritation of the oesophagus because stomach contents flow back into the oesophagus.
Refractory: not responding to treatment.
Regimen: a prescribed drug treatment plan, specifying which drugs are to be used, in what doses and on what schedule.
Reiki: the Usui healing system, known in the West as Reiki, has its roots in Taoism and Tendai Buddhism.
Reiter's syndrome/Reiter's disease: see reactive arthritis.
Relapse: the recurrence of disease.
Remission: restoration of the blood, bone marrow and general health of the patient to normal. Induced by chemotherapy and/or radiotherapy.
Renal: kidney-related.
Renin: an enzyme in the kidney that sets off a chain reaction to produce angiotensin II and raise blood pressure.
Renovascular: kidney blood vessel-related.
Replication: duplication.
Resection: removal of any part of the body.
Resistance: reduction in a pathogen's sensitivity to a particular drug. Resistance is thought to result mainly from a genetic mutation.
Respiration: breathing.
Restless leg syndrome: a discomfort in the legs which is relieved by moving or stimulating the legs. This feeling is difficult to describe and commonly referred to as a crawling, tingling or prickling sensation.
Retardation: delaying.
Reticuloendothelial system: the collection of macrophages and other white blood cells that ingest infectious organisms such as bacteria and viruses.
Retina: the multilayered, light-sensitive membrane lining the inner eyeball that sends visual images to the brain via the optic nerve.
Retinal: eye-related.
Retinal detachment: a condition in which a portion of the retina becomes separated from the inner wall of the eye.
Retinitis: inflammation of the retina, usually caused by infections such as CMV. If left untreated, it can lead to blindness.
Retinoic acid: a synthetic compound related to vitamin A which can stimulate cells to become fully mature.
Retinol: the principle form of vitamin A found in the body.
Retinopathy: eye-disease.
Retraction: moving backwards.
Retrosternal: behind the breastbone.
Retrovirus: a type of virus that, when not infecting a cell, stores its genetic information on a single-stranded RNA molecule instead of the more usual double-stranded DNA. HIV is an example of a retrovirus.
Rett Syndrome: a profoundly handicapping neurological disorder which only affects girls.
Reye's syndrome: a disease of the brain.
Rh incompatibility: a blood condition in which antibodies in a pregnant woman's blood can attack fetal blood cells, impairing the fetus's supply of oxygen and nutrients.
Rheumatic diseases: refers to all types of arthritis and rheumatism.
Rheumatic fever: infection of the heart valves, can occur in adults or children, though comparatively rare in the former. Far less common in developed countries than 60 years ago.
Rheumatism: a more general term used to describe any pain or inflammation in or around the bones, muscles, joints or tissues surrounding the joints. Thus 'rheumatism' includes 'arthritis'.
Rheumatoid arthritis: a common inflammatory disease of the joints.
Rheumatologist: a doctor who specializes in diagnosing and treating disorders that affect the joints, muscles, tendons, ligaments, and bones.
Rhinitis: inflammation of the nasal mucous membrane.
Rhinopharyngitis: inflammation of the space behind the nose.
Rhinoplasty: the repair of a defect of the nose.
Rhinorrhoea: a runny nose.
Rhonchus: wheezing.
Richter's syndrome: development of lymphoma in a patient who has chronic lymphocytic leukaemia.
RNA: (ribonucleic acid) a copy of the genetic code used by cells as a template for making proteins. It copies the message given out by the DNA.
Rosacea: the abnormal reddening of the face, particularly the nose and cheeks.
Rotator cuff: four muscle tendons that merge with the fibrous capsule enclosing the shoulder joint.
Rubella: a contagious viral infection associated with a rash.
Rubefacient: an agent that causes reddening and warming of the skin, often used as counter irritants for the relief of muscular pain.
Rubella: also known as German measles, rubella is a viral infection that can damage the nervous system in the developing fetus.
Rupture: a break or tear in any organ or soft tissue.

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