Medical dictionary

---

A |B| C |D | E |F | G |H | I |J | K |L | M |N | O |P | Q |R | S | T |U | V |W | XYZ

Sacroilitis: affecting the sacroiliac joint at the base of the spine.
Sacrum: triangular bone at base of spine.
Saliva: watery mucous secreted by the salivary glands into the mouth.
Salmonella: a bacterium that may cause intestinal infection and diarrhoea.
Sarcoidosis: there are two main types: acute, relatively benign sarcoidosis with sudden onset usually characterised by fever, inflammation of the skin and polyarthritis orpolyarthralgia; and chronicsarcoidosis which is a rarer form typically having a gradual onset with progressive and varied outcomes, including enlargedlymph nodes at the roots of the lungs. Further info.
Sarcoma: a malignant tumor of the skin and soft tissue.
Saturated fatty acids: fatty acids in which the molecule has no room for any more hydrogen atoms.
Scabies: a contagious itch caused by a mite.
Scalp: the part of the head that is normally covered with hair.
Scar: any mark left on damaged tissue after it has healed.
Scheuermann's disease: often seen in early adolescence; usually affects the thoracic spine presenting with a painlesskyphosis, but may affect the lumbar spine.
Sclerosis: hardening of some part of the body.
Scoliosis: lateral curvature of the spine (meaning in a sideways direction).
Scurvy: a disease caused by lack of vitamin C in the diet.
Seasonal Affective Disorder (SAD): A seasonal disruption of mood that occurs during the winter months and ceases with the advent of spring. Symptoms usually begin in September when days begin to shorten, and last through the winter into March when the days begin to lengthen again. Light plays a big part in its origin and in its treatment. In rarer instances, the seasonal disorder symptoms occur in the summer months and may be caused by an intolerance to heat. Further info.
Sebum: oily secretion of the sebaceous glands of the skin.
Secondary leukaemia: a leukaemia arising from either previouschemotherapy orradiotherapy or as the development of a pre-existing condition, such as myelodysplasia.
Secretin: a hormone made by the lining of the intestines that helps digest food.
Segmentation: the process by which muscles in the intestines move food and wastes through the body.
Selective dorsal root rhizotomy: a surgical procedure in which selected nerves are severed to reduce spasticity in the legs.
Semen: the combination of seminal and prostate fluid and sperm.
Sensitivity: the degree to which an organism is affected by a drug.
Sepsis: the presence of disease-causing organisms or their toxins in the blood or tissues and the associated inflammatory response to the infection.
Septic arthritis: usually caused by bacterial infections and can be a complication ofrheumatoid arthritis. However, other types of arthritis may also predispose the individual to septic arthritis. Symptoms may include acute pain and swelling, usually affecting only a single joint, although several joints may be affected simultaneously. Pneumonia or skin infection also characterise this condition. It generally affects more men than women.
Septicaemia: serious bacterial infection of the blood stream often associated with high fever.
Septum: a thin wall dividing two body cavities.
Sequelae: the complications that result from a disease.
Sero-negative: this term is often used to describe non-rheumatoid inflammatory joint disorders where the serum test Rheumatoid Factor (for rheumatoid arthritis) is negative. It essentially refers to any one of a group of inflammatory diseases sharing certain clinical characteristics:ankylosing spondylitis,Reiter's disease,reactive arthritis,psoriatic arthritis andspondylitis, arthritis with ulcerative colitis andCrohn's disease,uveitis, HLA-B27 linked peripheral arthritis and possibly other conditions. See also spondarthritis.
Serositis: inflammation of the delicate tissues covering internal organs and abdominal pain.
Serotonin: a neurotransmitter and hormone synthesised from the amino acid tryptophan in the gut and bronchi.
Serum: the part of the blood which remains after cells,platelets andfibrinogen have been removed, usually by allowing the blood to clot.
Sex chromosomes: the X and Y chromosomes determine the sex of an individual. Females have two X chromosomes: males have an X and a Y chromosome.
Shiatsu: Japanese massage based on yin/yang.
Shigellosis: infection with the bacterium Shigella causing a high fever, acute diarrhea, and dehydration.
Shingles (Herpes Zoster): a skin condition caused by reactivation of a Varicella zoster virus.
Siblings: brothers and/or Sisters.
Sickle cell disease: an inherited disease of red blood cells which can cause attacks of pain and damage to vital organs and can lead to early death.Further info.
Side effect: any reaction that results from a drug or therapy.
Sigmoid colon: the lower part of the colon that empties into the rectum.
Sigmoidoscopy: looking into the sigmoid colon and rectum with a flexible or rigid tube, called a sigmoidoscope.
Sinus: a hole or cavity in a bone or organ.
Sinusitis: inflammation of the nasal sinuses.
Sjögren's syndrome: this condition, also referred to as 'Dry Eye', often occurs in association with other rheumatic disorders: rheumatoid arthritis;systemic lupus erythematosus; or scleroderma, but can occur on its own without joint troubles (primary SS). Sjögren's Syndrome is a disorder in which eyes and mouth, and sometimes other mucous membranes, become unduly dry from lack of their usual lubricants.Further info.
Slapped cheek syndrome: an infection caused by a virus called a parvovirus. Further info.
Sleep apnoea: a debilitating sleep and breathing disorder defined as the cessation of breathing for 10 seconds or more (an apnoea) at least five times per hour of sleep. Further info.
Small intestine: the organ where most digestion occurs, it includes the duodenum, jejunum, and ileum.
Smegma: a thick, white, cheese-like secretion that collects between the labia and under the foreskin.
Soft tissue rheumatism: technically referred to as "regional periarticular" or 'soft tissue' diseases or disorders, this group covers an extremely common set of relatively minor conditions affecting the tissues surrounding a joint such as ligaments and tendons. Rheumatic pain can arise from damage to areas around joints, mostly caused by unaccustomed or repetitive usage, minor injury or by trauma. Some are particularly associated with a certain type of activity, 'tennis elbow' and 'housemaid's knee' being examples. In addition, more generalised pain can develop in the muscles or joints without arthritis, e.g. 'fibromyalgia'.
Somatostatin: a hormone in the pancreas.
Somatotropin: a hormone, released by the pituitary gland, that regulates growth.
Spasms: muscle movements such as those in the colon that cause pain, cramps, and diarrhoea.
Spastic diplegia: a form of cerebral palsy in which both arms and both legs are affected, the legs being more severely affected.
Spastic hemiplegia (or hemiparesis): a form ofcerebral palsy in which spasticity affects the arm and leg on one side of the body.
Spastic paraplegia (or paraparesis): a form ofcerebral palsy in which spasticity affects both legs but the arms are relatively or completely spared.
Spastic quadriplegia (or quadriparesis): a form ofcerebral palsy in which all four limbs are affected equally.
Spermatoceles: benign cysts of the scrotum.Further info.
Sphincter: a ring-like band of muscle that opens and closes an opening in the body.
Sphygmomanometer: an instrument used to measure blood pressure.
Spina bifida: is a nerve tube defect present at birth.
Spleen: the spleen acts as a "discriminating filter" of the blood. It can selectively remove oldred blood cells and bacteria and other foreign bodies. The spleen also acts as a store forplatelets.
Splenectomy: surgical removal of the spleen.
Splenomegaly: enlargement of thespleen.
Spondarthritis: this is a more precise and descriptive term used for those conditions called 'sero-negative' e.g.ankylosing spondylitis. Spondarthritis is also known as spondarthropathy, spondylarthritis, spondylarthropathy and spondyloarthropathy. Spondarthritides is the plural of spondarthritis. See also sero-negative.
Spondylitis:'inflammation' in the joints of the spine; it comes from the Greek word for verterbrae (spondylos).
Spondyloarthropathies: a group of rheumatic diseases that affect the spine, such as Reiter's syndrome andankylosing spondylitis.
Spondylolisthesis: refers to slipping, partial dislocation of one of the joints of the spine.
Spondylosis:osteoarthritis of small joints in the neck and back (i.e. cervical & lumbar); commonly present in all of us, often without causing any symptoms.
Sprain: injury to a joint in which the ligaments are overstretched.
Sputum: material coughed up from the respiratory tract.
Staging: an assessment of the spread of disease through the body, for example in lymphoma. It is of importance for the selection of optimal treatment.
Stammering: a wide range of behaviours. One person may get blocked or stuck on a certain word or sound, another may repeat sounds, another may go back in speech and take a run at the difficult word, and yet another may do all of these things and many more. Further info.
Staphylococcus: a genus of gram-positive bacteria that forms irregular clusters: found on skin, in skin glands on the nasal and other mucous membranes.
Stasis: reduction or cessation of flow.
Statins: a class of drugs used to lower blood cholesterol.
STD: sexually transmitted disease.
Steatorrhoea: a condition in which the body cannot absorb fat. Causes a buildup of fat in the stool and loose, greasy, and foul bowel movements.
Stem cells: the most primitive cells in the bone marrow from which all the various types of blood cell are derived.
Stenosis: the narrowing of a tube or duct.Stereognosia: difficulty perceiving and identifying objects using the sense of touch.
Stethoscope: an instrument used to listen to sounds in the body.
Stevens-Johnson Syndrome: a serious, sometimes fatal inflammatory disease characterized by fever, severe rash and blisters on the skin and open sores on the mucous membranes. The syndrome may be triggered by a severe allergic reaction to certain drugs.
Stoma: mouth or orifice.
Stomach: the organ between the oesophagus and the small intestine. The stomach is where digestion begins.
Stomatitis: inflammation of the mucous membrane of the mouth.
Stool: faeces.
Strabismus: misalignment of the eyes.
Streptococcus: a genus of Gram-positive bacteria containing spherical or ovoid cells which occur in pairs or short or long chains; some species are pathogenic.
Steroids: see corticosteroids.
subcutaneous injection: an injection into tissue immediately under the skin.
Stool: the solid wastes that pass through the rectum as bowel movements.
Strain: a variant characterized by specific genetic features.
Strawberry marks: raised red soft lumps on the skin usually the size of a 50p piece and look like a strawberry.Further info.
Stricture: the abnormal narrowing of a body opening. Also calledstenosis.
Stroke: damage to part of the brain rsulting from the breakdown in the blood supply which can be caused by a thrombus, anembolus or a bleed).
Stroma: the tissue that forms the framework of an organ.
Sturge-Weber: a condition which consists of a birth mark always involving the forehead and a similar blood vessel abnormality on the brain surface (often called an angioma). Further info.
Subcostal: below the ribs.
Subcutaneous: below the skin, also refers to injecting medicines directly under the skin. In the latter case, abbreviated SC.
Subdural hematoma: bleeding below the dura in the brain.
Subluxation: an incomplete dislocation of a joint.
Substrate: the compounds acted upon by anenzyme.
Subtype: a major subpopulation of a given organism, with a distinct genetic makeup.
Sudeck's atrophy/disease syndrome: seereactive arthritis.
Sugar: a class of carbohydrates that taste sweet.
Sulcus: a groove of furrow.
Supination: turning the forearm up, so that the palm faces upward.
Supine: lying on the back with the face upward.
Suppository: a solid, cone-shaped medicated substance that is administered by inserting it into the rectum, vagina, or urethra.
Supraventricular tachycardia (SVT): a sort of electrical short-circuit which allows the heart muscle to pump very fast.Further info.
Sweat test: an accurate, safe, and painless way to diagnose Cystic Fibrosis.
Stye (hordeolum): suppurative infection of a marginal gland of the eyelid. Inflammation of the sebaceous gland of an eyelash, or internal, acute purulent infection of a Meibomian gland.
Sympathetic nervous system: part of the nervous system with many functions, including control of the smooth muscles around the airways. Works together with the parasympathetic nervous system.
Sympathomimetic: denoting mimicking of action of the sympathetic system.
Symptoms: these are the physical signs of a disease.
Symphysis: growing together.
Symptomatology: the collected symptoms of a particular disease.
Syncope: fainting.
Syndrome: a collection of physical features which, when they occur together, enable a physician to recognise a certain condition.
Syngeneic: literally "sharing the same genes". It refers to bone marrow or peripheral blood stem cell transplants between identical twins.
Synovial fluid: the fluid produced by synovium to nourish and lubricate the joint.
Synovitis: inflammation of the joint
Synovium: the inner layer of the capsule that produces synovial fluid.
Syringe: an instrument used to inject or withdraw liquids.
Systemic: concerning or affecting the body as a whole. A systemic therapy is one that the entire body is exposed to, rather than just the target tissues affected by a disease.
Systemic lupus erythematosus (SLE): one of the connective tissue diseases, commonly called lupus. 'Systemic' - affecting many organs of the body; 'lupus' - affecting the skin by producing a rash on the face, hence the use of the term lupus which is latin for wolf; 'erythematosus' - simply means red, because in lupus, rashes are very common. Lupus is a rheumatic disease which is characterised by abnormalities of the immune system (which normally protects the body against infection). Further info.
Systole: the period in which a heart chamber is contracting.
Systolic blood pressure: the maximum pressure in the arteries as blood is forced out of the heart in ventricular systole.

A |B | C |D | E |F | G |H | I |J | K |L | M |N | O |P | Q |R | S | T |U | V |W | XYZ