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Glossary - All

Displaying glossary terms: 1751 - 1800 of 2011 in total
stages of change
A model for how people make changes in their lives. According to this model, changes in behavior are made gradually and in relatively distinct stages.
staging
The process of determining how far cancer has progressed. Staging is often used to determine the best course of treatment.
standardized extract
An herbal product in which what is believed to be the active ingredient meets an established standard of strength.
statins
Cholesterol-lowering medications that interfere with the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase; also known as HMG-CoA reductase inhibitors. Statins work by changing the way the liver processes lipids.
stenosis
An abnormal narrowing of a passageway, such as a blood vessel, or other type of opening in the body.
Related health topics: Coronary Artery Disease
stent
A wire mesh device inserted into an artery to prop it open once a blockage has been cleared by angioplasty.
sterilization
1) A surgical procedure or other method that results in a person being unable to reproduce. 2) The process by which materials are thoroughly cleaned of all organisms that could cause disease or infection.
steroids
Another term for corticosteroids?steroid medications made to mimic hormones produced naturally by the adrenal glands. They are used to treat a wide range of health problems.
Related health topics: Radiation Therapy
stimulant
A substance that speeds up chemical reactions inside cells and provides a boost of energy. Examples include caffeine and amphetamine.
Related health topics: Acne, Eczema
stomach
The sac-like organ of the digestive system between the esophagus and the duodenum which breaks down food and moves it along to the small intestine to be digested.
strain
A stretched or torn muscle or tendon, usually caused by accident, misuse, or overuse.
stratum corneum
The most superficial layer of the epidermis.
strength
The ability of muscles to exert force.
strength training
Popular term for exercises that harness resistance supplied by body weight, free weights such as dumbbells or weighted cuffs, resistance bands, or specialized machines; also known as resistance training or weight training.
streptokinase
A thrombolytic (clot-dissolving) agent designed to dissolve the blood clots that block an artery during a heart attack or stroke.
stress
An innate survival response in which certain hormones are released, increasing blood flow to the brain or heart. The stress response leads to an energy surge, enabling a person to flee dangerous situations. Ongoing stress, however, can sap energy and damage health.
stress fracture
A hairline crack in a bone that usually occurs from overuse; left untreated, this may lead to displacement of the bones.
stress response
Physiological changes, such as quickened breathing and heartbeat and increased blood pressure, brought on by stress hormones released in response to a real or perceived threat to safety. Also called the fight-or-flight response.
stress test
A diagnostic test in which cardiovascular measurements such as heart rate, blood pressure, and electrical activity are recorded while the heart is being stressed (usually by having the person exercise on a treadmill or bicycle).
stressors
Stressful events or circumstances that may be real or perceived threats to equilibrium and well-being.
stria
A line, streak, or band, such as the stretch marks that occur in pregnancy.
Related health topics: Post-Traumatic Stress Disorder
stricture
The abnormal narrowing of a hollow passage in the body, such as the esophagus or the urethra.
stroke
Blockage or rupture of a blood vessel supplying the brain; often leads to impaired brain function or death.
stupor
A state of lethargy and unresponsiveness.
subacute
A disease or condition that progresses slower than an acute condition but faster than a chronic condition.
Related health topics: Hemorrhagic Stroke
subacute thyroiditis
A painful version of thyroid inflammation caused by viral infection. Symptoms are flu-like and include fever, muscle aches and pains, and a painful, swollen thyroid gland. Also known as de Quervain's thyroiditis.
subarachnoid hemorrhage
A hemorrhagic stroke that occurs when a blood vessel on the surface of the brain bursts and bleeds into the space between the brain and the skull; usually caused by an aneurysm or other blood vessel malformation.
subarachnoid space
Space inside the brain where cerebrospinal fluid circulates.
Related health topics: Concussion
subcutaneous
Beneath the skin.
subcutaneous tissue
Deepest layer of skin, which consists of connective tissue and fat.
subdural hematoma
A blood clot in the brain between the cerebral cortex and the dura.
subendocardial myocytes
Heart-muscle cells on the inside of the heart chambers; these cells are highly susceptible to damage from blockages of the major coronary arteries.
Related health topics: Concussion
substance abuse
Continued substance use despite substance-related social or interpersonal problems.
substance dependence
A condition characterized by excessive and often compulsive substance use, impaired control over substance use, continued use of substances despite adverse consequences, and withdrawal symptoms that emerge when the substance use is discontinued.
subunit vaccines
Vaccines using only part of a microbe?the antigens?to elicit an immune response; these vaccines tend to cause fewer adverse reactions than vaccines which contain the whole microbe.
sulcus
The V-shaped hollow at the margin of the tooth and gum.
sulfonylureas
A class of medications that works by stimulating the pancreas to produce more insulin.
sundowning
Confusion or disorientation beginning at the end of the day and continuing into the night; often occurs in people with Alzheimer's disease or vascular dementia.
superior vena cava
The major vein that carries deoxygenated blood from the upper body to the heart.
superset
Two or more exercises combined for a more vigorous workout. During a superset, all the reps of exercise A are performed and then all the reps of exercise B before resting.
suppository
A solid form of medication that is inserted in the rectum or vagina and absorbed into the bloodstream.
suprachiasmatic nucleus
A small group of nerve cells located in the hypothalamus that controls the sleep/wake cycle.
Related health topics: Bulimia
supraventricular tachycardia
An abnormally fast heartbeat originating in heart tissue above the ventricles.
suture
The process of sewing tissues together after surgery; or the stitch itself.
sympathetic nervous system
An offshoot of the autonomic nervous system; it sends signals to prepare the body for action when stress hormones are released in response to perceived or real dangers.
symptom-limited exercise stress test
Exercise test, usually using a treadmill or bicycle, that increases in difficulty at set stages and is stopped when the person develops chest pain, breathlessness, or extreme fatigue.
Related health topics: Neuroblastoma
synapse
The junction between two neurons, across which chemical neurotransmitters carry messages.
syncope
Fainting or loss of consciousness caused by a temporary shortage of oxygen in the brain.
synovectomy
Surgical removal of the synovial membrane that lines the joints.
synovial fluid
A thick liquid that lubricates the joints and tendons.