The following are health and medical definitions of terms that appear in the Stroke article.
Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer ). See the entire definition of Abnormal
Abscess: A local accumulation of pus anywhere in the body. The following are some examples of abscesses: - A skin abscess is better known as a common boil;
- A peritonsillar abscess is a persistent collection of pus behind the tonsils; and
- A perianal abscess is a pool of pus that forms next to the anus, often causing considerable tenderness and swelling in that area and pain on sitting down and on defecating.
Acute: Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care. See the entire definition of Acute
Acute illness: A disease with an abrupt onset and usually a short course.
Adverse reaction: In pharmacology, any unexpected or dangerous reaction to a drug. An unwanted effect caused by the administration of a drug. The onset of the adverse reaction may be sudden or develop over time. See the entire definition of Adverse reaction
Alteplase: Generic name of a tissue plasminogen activator produced by recombinant DNA technology. The brand name is Activase. See: Tissue plasminogen activator.
Amaurosis fugax: A symptom described as a shade coming down over the eye. A partial or complete loss of sight that is temporary. See the entire definition of Amaurosis fugax
Anatomy: The study of form. Gross anatomy involves structures that can be seen with the naked eye. It is as opposed to microscopic anatomy (or histology) which involves structures seen under the microscope. Traditionally, both gross and microscopic anatomy have been studied in the first year of medical school in the U.S. The most celebrated textbook of anatomy in the English-speaking world is Gray's Anatomy, still a useful reference book. The word "anatomy" comes from the Greek ana- meaning up or through + tome meaning a cutting. Anatomy was once a "cutting up" because the structure of the body was originally learned through dissecting it, cutting it up. The abbreviation for anatomy is anat.
Anemia: The condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood. The oxygen-carrying capacity of the blood is, therefore, decreased. See the entire definition of Anemia
Aneurysm: A localized widening (dilatation) of an artery, vein, or the heart. At the area of an aneurysm, there is typically a bulge and the wall is weakened and may rupture. The word "aneurysm" comes from the Greek "aneurysma" meaning "a widening."
Angiogram: An x-ray of blood vessels which can be seen because the patient receives an injection of dye to outline the vessels on the x-ray.
Angiography: A procedure performed to view blood vessels after injecting them with a radioopaque dye that outlines them on x-ray. This technique can be usefully used to look at arteries in many areas of the body, including the brain, neck (carotids), heart, aorta, chest, pulmonary circuit, kidneys, gastrointestinal tract, and limbs.
Anterior: The front, as opposed to the posterior. The anterior surface of the heart is toward the breast bone (the sternum). See the entire definition of Anterior
Anticoagulant: Any agent used to prevent the formation of blood clots. See the entire definition of Anticoagulant
Aphasia: One in a group of speech disorders in which there is a defect or loss of the power of expression by speech, writing, or signs, or a defect or loss of the power of comprehension of spoken or written language. See, for example, auditory aphasia . See the entire definition of Aphasia
Arms: An appendage in anatomy and in clinical trials. See: Arm.
Arteriole: A small branch of an artery (a vessel that carries blood high in oxygen away from the heart to the body) leading to a capillary. The oxygenated hemoglobin (oxyhemoglobin) makes the blood in arteries and arterioles look bright red. See the entire definition of Arteriole
Artery: A vessel that carries blood high in oxygen content away from the heart to the farthest reaches of the body. Since blood in arteries is usually full of oxygen, the hemoglobin in the red blood cells is oxygenated. The resultant form of hemoglobin (oxyhemoglobin) is what makes arterial blood look bright red. See the entire definition of Artery
Aspirin: A good example of a tradename that entered into the language, Aspirin was once the Bayer trademark for acetylsalicylic acid . See the entire definition of Aspirin
Atherosclerosis: A process of progressive thickening and hardening of the walls of medium-sized and large arteries as a result of fat deposits on their inner lining. See the entire definition of Atherosclerosis
Atherosclerotic: Pertaining to atherosclerosis, the process of progressive thickening and hardening of the walls of arteries from fat deposits on their inner lining. Atherosclerotic heart disease is the leading cause of death in the US.
Atrial: Pertaining to the atria, the upper chambers of the heart, as in atrial fibrillation and atrial septal defect.
Atrial fibrillation: Abnormal irregular heart rhythm with chaotic generation of electrical signals in the atria of the heart. Familiarly called atrial fib.
Bacteria: Single-celled microorganisms which can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). See the entire definition of Bacteria
Bladder: Any pouch or other flexible enclosure that can hold liquids or gases but usually refers to the hollow organ in the lower abdomen that stores urine -- the urinary bladder. The kidneys filter waste from the blood and produce urine, which enters the bladder through two tubes called ureters. Urine leaves the bladder through another tube, the urethra . In women, the urethra is a short tube that opens just in front of the vagina . In men, it is longer, passing through the prostate gland and then the penis . Infection of the bladder is called cystitis . See the entire definition of Bladder
Blood clot: Blood that has been converted from a liquid to a solid state. Also called a thrombus . See the entire definition of Blood clot
Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".
Blood sugar: Blood glucose. See also: High blood sugar; Low blood sugar.
Bowel: Another name for the intestine . The small bowel and the large bowel are the small intestine and large intestine , respectively. See the entire definition of Bowel
Brain: That part of the central nervous system that is located within the cranium ( skull ). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres." See the entire definition of Brain
Brainstem: The lowest part of the brain which merges with the spinal cord and provides the major route by which the upper realms of the brain send information to, and receives information from, the spinal cord and peripheral nerves. The brainstem consists of the medulla oblongata, midbrain, and pons. All but two of the 12 cranial nerves originate in the brainstem. The brainstem influences basic processes such as alertness, breathing, blood pressure, and heart rate.
C-reactive protein: A plasma protein that rises in the blood with the inflammation from certain conditions. See the entire definition of C-reactive protein
Calcium: A mineral found mainly in the hard part of bones, where it is stored. Calcium is added to bones by cells called osteoblasts and is removed from bones by cells called osteoclasts. Calcium is essential for healthy bones. It is also important for muscle contraction, heart action, nervous system maintenance, and normal blood clotting. Food sources of calcium include dairy foods, some leafy green vegetables such as broccoli and collards, canned salmon, clams, oysters, calcium-fortified foods, and tofu. According to the National Academy of Sciences, adequate intake of calcium is 1,200 milligrams a day (four glasses of milk) for men and women 51 and older, 1,000 milligrams a day for adults 19 through 50, and 1,300 milligrams a day for children 9 through 18. The upper limit for calcium intake is 2.5 grams daily.
Cancer: An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread). See the entire definition of Cancer
Cardiac: Having to do with the heart. See the entire definition of Cardiac
Cardiac arrest: A medical emergency with absent or inadequate contraction of the left ventricle of the heart that immediately causes bodywide circulatory failure. The signs and symptoms include loss of consciousness; rapid shallow breathing progressing to apnea (absence of breathing); profoundly low blood pressure ( hypotension ) with no pulses that can be felt over major arteries; and no heart sounds. See the entire definition of Cardiac arrest
Cardiology: The study and treatment of heart disorders.
Cardiovascular: The circulatory system comprising the heart and blood vessels which carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them. See the entire definition of Cardiovascular
Carotid: Pertaining to the carotid artery and the area near that key artery located in the front of the neck though which blood from the heart goes to the brain. See the entire definition of Carotid
Carotid artery: A key artery located in the front of the neck though which blood from the heart goes to the brain. See the entire definition of Carotid artery
Carotid endarterectomy: Endarterectomy (a surgical procedure designed to clean out material occluding an artery) done on the carotid artery (a major artery in the neck that supplies blood to the brain) to restore normal blood flow through it to the brain and prevent a stroke.
Catheter: A thin, flexible tube . For example, a catheter placed in a vein provides a pathway for giving drugs, nutrients, fluids, or blood products. Samples of blood can also be withdrawn through the catheter. See the entire definition of Catheter
Cerebellum: The portion of the brain in the back of the head between the cerebrum and the brain stem. The cerebellum controls balance for walking and standing and other complex motor functions.
Cerebral: Pertaining to the brain, the cerebrum or the intellect. See the entire definition of Cerebral
Cerebral edema : Accumulation of excessive fluid in the substance of the brain. The brain is especially susceptible to injury from edema, because it is located within a confined space and cannot expand. See the entire definition of Cerebral edema
Cerebrovascular: Pertaining to the blood vessels and, especially, the arteries that supply the brain. As in cerebrovascular accident or cerebrovascular disease.
Cerebrovascular accident: The sudden death of some brain cells due to lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A CVA is also referred to as a stroke . See the entire definition of Cerebrovascular accident
Chest: The area of the body located between the neck and the abdomen . The chest contains the lungs , the heart and part of the aorta . The walls of the chest are supported by the dorsal vertebrae , the ribs , and the sternum . See the entire definition of Chest
Cholesterol: The most common type of steroid in the body, cholesterol has gotten something of a bad name. However, cholesterol is a critically important molecule. See the entire definition of Cholesterol
Circulation: The movement of fluid in a regular or circuitous course. Although the noun "circulation" does not necessarily refer to the circulation of the blood, for all practical purposes today it does. Heart failure is an example of a problem with the circulation.
Clinical trial: See: Clinical trials. See also: Inconclusive clinical trial; Negative clinical trial; Non-inferior clinical trial; Positive clinical trial.
Cocaine: The most potent stimulant of natural origin, a bitter addictive anesthetic (pain blocker) which is extracted from the leaves of the coca scrub (Erythroxylon coca) indigenous to the Andean highlands of South America. See the entire definition of Cocaine
Coma: A state of deep unarousable unconsciousness. See the entire definition of Coma
Complication: In medicine, an additional problem that arises following a procedure, treatment or illness and is secondary to it. A complication complicates the situation. See the entire definition of Complication
Computerized tomography: Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them in pictures. See the entire definition of Computerized tomography
CT scan: Computerized tomography scan. Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them into pictures on a screen. CT stands for computerized tomography. See the entire definition of CT scan
CVA: Cerebrovascular accident.
Decubitus: Lying down. A decubitus ulcer is a bed sore, the consequence of lying in one position too long. The Latin "decubitus" (meaning lying down) is related to "cubitum" (the elbow) reflecting the fact the Romans habitually rested on their elbows when they reclined.
Deep vein thrombosis: A blood clot ( thrombus ) in a deep vein in the thigh or leg. The clot can break off as an embolus and make its way to the lung, where it can cause respiratory distress and respiratory failure . See the entire definition of Deep vein thrombosis
Depression : An illness that involves the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression. See the entire definition of Depression
Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus . Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria). See the entire definition of Diabetes
Diabetes mellitus: Better known just as " diabetes " -- a chronic disease associated with abnormally high levels of the sugar glucose in the blood. Diabetes is due to one of two mechanisms: (1) Inadequate production of insulin (which is made by the pancreas and lowers blood glucose) or (2) Inadequate sensitivity of cells to the action of insulin. The two main types of diabetes correspond to these two mechanisms and are called insulin dependent (type 1) and non-insulin dependent (type 2) diabetes. In type 1 diabetes there is no insulin or not enough of it. In type 2 diabetes, there is generally enough insulin but the cells upon it should act are not normally sensitive to its action. See the entire definition of Diabetes mellitus
Diagnosis: 1 The nature of a disease ; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies . 3 The identification of any problem. The diagnosis was a plugged IV. See the entire definition of Diagnosis
Dizziness : Painless head discomfort with many possible causes including disturbances of vision, the brain, balance (vestibular) system of the inner ear, and gastrointestinal system. Dizziness is a medically indistinct term which laypersons use to describe a variety of conditions ranging from lightheadedness, unsteadiness to vertigo. See the entire definition of Dizziness
Doppler ultrasound: A form of ultrasound that can detect and measure blood flow. Doppler ultrasound depends on the Doppler effect, a change in the frequency of a wave resulting here from the motion of a reflector, the red blood cell . See the entire definition of Doppler ultrasound
ECG: Abbreviation for electrocardiogram or EKG. The K is from "kardio" (in German).
Edema: The swelling of soft tissues as a result of excess water accumulation. See the entire definition of Edema
Electrocardiogram : A recording of the electrical activity of the heart. An electrocardiogram is a simple, non-invasive procedure. Electrodes are placed on the skin of the chest and connected in a specific order to a machine that, when turned on, measures electrical activity all overaround the heart. Output is usually in the form of a long scroll of paper displaying a printed graph of activity. Newer models output the data directly to a computer and screen, although a print-out may still be made. See the entire definition of Electrocardiogram
Electrolyte: An electrolyte is a substance that will dissociate into ions in solution and acquire the capacity to conduct electricity. The electrolytes include sodium, potassium, chloride, calcium and phosphate. Informally, called lytes. (The clue to the word electrolyte is in the lyte which comes from the Greek lytos meaning that may be dissolved.) See the entire definition of Electrolyte
Emboli: Something that travels through the bloodstream, lodges in a blood vessel and blocks it. Examples of emboli are a detached blood clot, a clump of bacteria , and foreign material such as air. See the entire definition of Emboli
Embolism: The obstruction of a blood vessel by a foreign substance or a blood clot blocking the vessel. Something travels through the bloodstream, lodges in a vessel and plugs it. See the entire definition of Embolism
Encephalitis: Inflammation of the brain. Encephalitis occurs, for example, in 1 in 1,000 cases of measles . It may start (up to 3 weeks) after onset of the measles rash and present with high fever , convulsions, and coma. It usually runs a blessedly short course with full recovery within a week. Or it may eventuate in central nervous system impairment or death. See the entire definition of Encephalitis
Endarterectomy: An operation to clean out an artery and restore normal blood flow through the artery. An endarterectomy is basically a "Rotorooter" procedure. It removes diseased material from the inside of an artery, and also removes any occluding atheromatous deposits, the aim being to leave a smooth lining within the vessel, so the blood can flow normally. See the entire definition of Endarterectomy
Esophagus: The tube that connects the pharynx (throat) with the stomach. The esophagus lies between the trachea (windpipe) and the spine. It passes down the neck, pierces the diaphragm just to the left of the midline, and joins the cardiac (upper) end of the stomach. In an adult, the esophagus is about 25 centimeters (10 inches) long. When a person swallows, the muscular walls of the esophagus contract to push food down into the stomach. Glands in the lining of the esophagus produce mucus, which keeps the passageway moist and facilitates swallowing. Also known as the gullet or swallowing tube. From the Greek oisophagos, from oisein meaning to bear or carry + phagein, to eat.
Fibrillation: In matters of the heart (cardiology), fibrillation is incoordinate twitching of the heart muscle fibers. See the entire definition of Fibrillation
Foramen: A natural opening. Although a foramen is usually through bone, it can be an opening through other types of tissue, as with the foramen ovale in the heart. The plural of foramen is foramina.
Foramen ovale: An oval opening between the two upper chambers of the heart (the atria) that is a normal feature of the fetal and neonatal (newborn) circulation. The foramen ovale normally closes on its own by 3 months of age. See the entire definition of Foramen ovale
Fungus: A single-celled or multicellular organism. Fungi can be true pathogens (such as histoplasmosis and coccidioidomycosis) that cause infections in healthy persons or they can be opportunistic pathogens (such as aspergillosis, candidiasis, and cryptococcosis) that cause infections in immunocompromised persons (including cancer patients, transplant recipients, and persons with AIDS). An example of a common fungus is the yeast organism which causes thrush and diaper rash (diaper dermatitis). Fungi are also used for the development of antibiotics, antitoxins, and other drugs used to control various human diseases.
Genes: The basic biological units of heredity . Segments of deoxyribonucleic acid (DNA) needed to contribute to a function. See the entire definition of Genes
Genetic: Having to do with genes and genetic information.
Glucose: The simple sugar (monosaccharide) that serves as the chief source of energy in the body. Glucose is the principal sugar the body makes. The body makes glucose from proteins, fats and, in largest part, carbohydrates. Glucose is carried to each cell through the bloodstream. Cells, however, cannot use glucose without the help of insulin . Glucose is also known as dextrose. See the entire definition of Glucose
Groin: In anatomy, the area where the upper thigh meets the trunk. More precisely, the fold or depression marking the juncture of the lower abdomen and the inner part of the thigh. See the entire definition of Groin
Headache : A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck. Headache, like chest pain or back ache, has many causes. See the entire definition of Headache
Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest. See the entire definition of Heart
Heart attack: The death of heart muscle due to the loss of blood supply. The loss of blood supply is usually caused by a complete blockage of a coronary artery, one of the arteries that supplies blood to the heart muscle. Death of the heart muscle, in turn, causes chest pain and electrical instability of the heart muscle tissue. See the entire definition of Heart attack
Hemiplegia: Paralysis of one side of the body. From hemi- (half) + plege (a blow, stroke).
Hemorrhage: Bleeding or the abnormal flow of blood. See the entire definition of Hemorrhage
Heparin: An anticoagulant (anti-clotting) medication. Heparin is useful in preventing thromboembolic complications (clots that travel from their site of origin through the blood stream to clog up another vessel). Heparin is also used in the early treatment of blood clots in the lungs (pulmonary embolisms).
High blood pressure : Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90. See the entire definition of High blood pressure
Holter monitor: A type of portable heart monitor. The Holter monitor is a small portable electrocardiogram ( ECG ). The device is worn in a pouch around the neck or waist. It keeps a record of the heart rhythm, typically over a 24-hour period, while the patient keeps a diary recording their activities and any symptoms they may feel. The ECG recording is then correlated with the person's record of their activities and symptoms. The Holter monitor is useful for identifying disturbances which are sporadic and which are not readily identified with the usual resting electrocardiogram test. See the entire definition of Holter monitor
Homocystinuria: A genetic disease due to an enzyme deficiency. Among other events, there is a buildup of the amino acid homocystine. Progressive mental retardation is common in untreated cases. The finding of vascular disease and premature arteriosclerosis in persons with homocystinuria led to the theory that homocystine may be a factor in heart disease. See the entire definition of Homocystinuria
Hypertension: High blood pressure , defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90. See the entire definition of Hypertension
Incidence: The frequency with which something, such as a disease, appears in a particular population or area. In disease epidemiology, the incidence is the number of newly diagnosed cases during a specific time period. The incidence is distinct from the prevalence which refers to the number of cases alive on a certain date. See the entire definition of Incidence
Incontinence: Inability to control excretions. Urinary incontinence is inability to keep urine in the bladder. Fecal incontinence is inability to retain feces in the rectum.
Infarct: An area of tissue death due to a local lack of oxygen . See the entire definition of Infarct
Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person. See the entire definition of Infection
Inflammation: A basic way in which the body reacts to infection , irritation or other injury, the key feature being redness, warmth, swelling and pain . Inflammation is now recognized as a type of nonspecific immune response . See the entire definition of Inflammation
Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.
Inpatient: A patient whose care requires a stay in a hospital. As opposed to an outpatient. The term inpatient dates back to at least 1760. The case of an inpatient was referred to an incase.
Intervention: The act of intervening, interfering or interceding with the intent of modifying the outcome. In medicine, an intervention is usually undertaken to help treat or cure a condition. For example, early intervention may help children with autism to speak. "Acupuncture as a therapeutic intervention is widely practiced in the United States," according to the National Institutes of Health. From the Latin intervenire, to come between.
Interventional: Pertaining to the act of intervening, interfering or interceding with the intent of modifying the outcome. As, for example, an interventional radiologist.
Interventional radiologist: A radiologist who uses image guidance methods to gain access to vessels and organs. Interventional radiologists can treat certain conditions through the skin (percutaneously) that might otherwise require surgery . The technology includes the use of balloons, catheters, microcatheters, stents, and therapeutic embolization (deliberately clogging up a blood vessel ). The specialty of interventional radiology overlaps with other fields, including interventional cardiology , vascular surgery, endoscopy , laparoscopy , and other minimally invasive techniques, such as biopsies. Specialists performing interventional radiology procedures today include not only radiologists but also other types of physicians such as general surgeons, vascular surgeons, cardiologists, gastroenterologists, gynecologists, and urologists. See the entire definition of Interventional radiologist
Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination. See the entire definition of Kidney
Leg: In popular usage, the leg extends from the top of the thigh down to the foot. However, in medical terminology, the leg refers to the portion of the lower extremity from the knee to the ankle. See the entire definition of Leg
Lungs: The lungs are a pair of breathing organs located with the chest which remove carbon dioxide from and bring oxygen to the blood. There is a right and left lung.
Medical history: 1. In clinical medicine, the patient's past and present which may contain clues bearing on their health past, present, and future. The medical history, being an account of all medical events and problems a person has experienced, including psychiatric illness, is especially helpful when a differential diagnosis is needed. 2. The history of medicine.
Membrane: A very thin layer of tissue that covers a surface.
Meningitis: Inflammation of the meninges, usually due to a bacterial infection but sometimes from viral, protozoan, or other causes (in some cases the cause cannot be determined). See the entire definition of Meningitis
Metabolism: The whole range of biochemical processes that occur within us (or any living organism). Metabolism consists both of anabolism and catabolism (the buildup and breakdown of substances, respectively). The term is commonly used to refer specifically to the breakdown of food and its transformation into energy.
Migraine: Usually, periodic attacks of headaches on one or both sides of the head. These may be accompanied by nausea, vomiting, increased sensitivity of the eyes to light (photophobia), increased sensitivity to sound (phonophobia), dizziness , blurred vision, cognitive disturbances, and other symptoms. Some migraines do not include headache, and migraines may or may not be preceded by an aura. See the entire definition of Migraine
Migraine headache: The most common type of vascular headache involving abnormal sensitivity of arteries in the brain to various triggers resulting in rapid changes in the artery size due to spasm (constriction). Other arteries in the brain and scalp then open (dilate), and throbbing pain is perceived in the head. The tendency to migraine is inherited and appears to involve serotonin, a chemical in the brain involved in the transmission of nerve impulses that trigger the release of substances in the blood vessels that in turn cause the pain of the migraine. These nerve impulses cause the flashing lights and other sensory phenomena known as an aura that may accompany a migraine . Not all severe headaches are migraines and not all migraines are severe. See the entire definition of Migraine headache
Motor: In medicine, having to do with the movement of a part of the body. Something that produces motion or refers to motion. For example, a motor neuron is a nerve cell that conveys an impulse to a muscle causing it to contract. The term "motor" today is also applied to a nerve that signals a gland to secrete. Motor is as opposed to sensory.
MRA:The magnetic resonance angiogram, or MRA, is a noninvasive test that has demonstrated usefulness in defining the anatomy of blood vessels of certain size in the head and neck. MRA serves as a complement to traditional MRI scanning in evaluation of the brain and neck. See the entire definition of MRA
MRI: Abbreviation and nickname for magnetic resonance imaging. For more information, see: Magnetic Resonance Imaging; Paul C. Lauterbur; Peter Mansfield.
Nausea: Nausea, is the urge to vomit. It can be brought by many causes including, systemic illnesses, such as influenza, medications, pain, and inner ear disease. When nausea and/or vomiting are persistent, or when they are accompanied by other severe symptoms such as abdominal pain, jaundice, fever, or bleeding, a physician should be consulted.
Neck: The part of the body joining the head to the shoulders. Also, any narrow or constricted part of a bone or organ that joins its parts as, for example, the neck of the femur bone. See the entire definition of Neck
Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system.
Neurological: Having to do with the nerves or the nervous system.
Neurologist: A doctor who specializes in the diagnosis and treatment of disorders of the nervous system.
Neurology: The medical specialty concerned with the diagnosis and treatment of disorders of the nervous system -- the brain, the spinal cord, and the nerves. See the entire definition of Neurology
NINDS: Stands for the National Institute of Neurological Disorders and Stroke, one of the National Institutes of Health in the U.S., whose mission is to "support and conduct research and research training on the normal structure and function of the nervous system and on the causes, prevention, diagnosis, and treatment of more than 600 nervous system disorders including stroke, epilepsy, multiple sclerosis, Parkinson's disease, head and spinal cord injury, Alzheimer's disease, and brain tumors."
Normal range: By convention, the normal range for whatever (a particular test, condition, symptom, behavior, etc.) is set to cover ninety-five percent (95%) of all values from the general population. Five percent (5%) of results consequently fall outside the normal range. Values that prove normal can therefore sometimes be outside the normal range. See the entire definition of Normal range
Nurse: 1) A person trained, licensed, or skilled in nursing. 2) To feed an infant at the breast.
Nursing: 1) Profession concerned with the provision of services essential to the maintenance and restoration of health by attending the needs of sick persons. 2) Feeding a infant at the breast.
Nutrition : 1) The science or practice of taking in and utilizing foods. 2) A nourishing substance, such as nutritional solutions delivered to hospitalized patients via an IV or IG tube. See the entire definition of Nutrition
Onset: In medicine, the first appearance of the signs or symptoms of an illness as, for example, the onset of rheumatoid arthritis . There is always an onset to a disease but never to the return to good health. The default setting is good health. See the entire definition of Onset
Operation: Although there are many meanings to the word "operation", in medicine it refers to a surgical procedure. See the entire definition of Operation
Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life. See the entire definition of Oxygen
Paralysis: Loss of voluntary movement (motor function). Paralysis that affects only one muscle or limb is partial paralysis, also known as palsy; paralysis of all muscles is total paralysis, as may occur in cases of botulism.
Peripheral: Situated away from the center, as opposed to centrally located. See the entire definition of Peripheral
Peripheral vascular disease: A disease of blood vessels outside the heart. Peripheral vascular disease (PVD) affects the peripheral circulation , as opposed to the cardiac circulation. PVD comprises diseases of both peripheral arteries and peripheral veins. PVD is sometimes incorrectly used as a synonym for peripheral artery disease (PAD). Intermittent claudication due to inadequate blood flow to the leg is an example of peripheral artery disease (PAD) while varicose veins and spider veins are examples of peripheral vein disease. See the entire definition of Peripheral vascular disease
Physical therapy: A branch of rehabilitative health that uses specially designed exercises and equipment to help patients regain or improve their physical abilities. Physical therapists work with many types of patients, from infants born with musculoskeletal birth defects, to adults suffering from sciatica or the after- effects of injury, to elderly post-stroke patients.
Plaque: 1. An semi-hardened accumulation of substances from fluids that bathe an area. Examples include dental plaque and cholesterol plaque. See the entire definition of Plaque
Pneumonia: Inflammation of one or both lungs with consolidation. Pneumonia is frequently but not always due to infection. The infection may be bacterial, viral, fungal or parasitic. Symptoms may include fever, chills, cough with sputum production, chest pain, and shortness of breath.
Posterior: The back or behind, as opposed to the anterior. See the entire definition of Posterior
Predispose: To make more likely or render susceptible. Smoking predisposes to a number of diseases, including esophageal cancer.
Prognosis: 1. The expected course of a disease . 2. The patient's chance of recovery. The prognosis predicts the outcome of a disease and therefore the future for the patient . His prognosis is grim, for example, while hers is good. See the entire definition of Prognosis
Protein: A large molecule composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein. See the entire definition of Protein
Proteins: Large molecules composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein. See the entire definition of Proteins
Pulmonary: Having to do with the lungs. (The word comes from the Latin pulmo for lung).
Pulmonary embolism: The obstruction of the pulmonary artery or a branch of it leading to the lungs by a blood clot, usually from the leg, or foreign material causing sudden closure of the vessel. (Embolus is from the Greek "embolos" meaning plug.) See the entire definition of Pulmonary embolism
Pus: A thick whitish-yellow fluid which results from the accumulation of white blood cells (WBCs), liquified tissue and cellular debris. Pus is commonly a site of infection or foreign material in the body.
Quality of life: An important consideration in medical care, quality of life refers to the patient's ability to enjoy normal life activities. Some medical treatments can seriously impair quality of life without providing appreciable benefit, while others greatly enhance quality of life.
Radiologist: A physician specialized in radiology , the branch of medicine that uses ionizing and nonionizing radiation for the diagnosis and treatment of disease. See the entire definition of Radiologist
Recurrence: The return of a sign, symptom or disease after a remission. The reappearance of cancer cells at the same site or in another location is, unfortunately, a familiar form of recurrence. See the entire definition of Recurrence
Rehabilitation: The process of restoration of skills by a person who has had an illness or injury so as to regain maximum self-sufficiency and function in a normal or as near normal manner as possible. For example, rehabilitation after a stroke may help the patient walk again and speak clearly again. See the entire definition of Rehabilitation
Resuscitate: To restore to life. Derived from the Latin resuscitare, to reawaken.
Risk factor: Something that increases a person's chances of developing a disease.
Rupture: A break or tear in any organ (such as the spleen) or soft tissue (such as the achilles tendon). Rupture of the appendix is more likely among uninsured and minority children when they develop appendicitis.
Scan: As a noun, the data or image obtained from the examination of organs or regions of the body by gathering information with a sensing device. See the entire definition of Scan
Sedimentation rate : A blood test that detects and monitors inflammation in the body. It measures the rate at which red blood cells (RBCs) in a test tube separate from blood serum over time, becoming sediment in the bottom of the test tube. The sedimentation rate increases with more inflammation. Also called the erythrocyte sedimentation rate. Abbreviated as sed rate or ESR. See the entire definition of Sedimentation rate
Sensation: In medicine and physiology , sensation refers to the registration of an incoming ( afferent ) nerve impulse in that part of the brain called the sensorium , which is capable of such perception. Therefore, the awareness of a stimulus as a result of its perception by sensory receptors. (Sensory is here synonymous with sensation.) See the entire definition of Sensation
Skull: The skull is a collection of bones which encase the brain and give form to the head and face. The bones of the skull include the following: the frontal, parietal, occipital, temporal, sphenoid, ethmoid, zygomatic, maxilla, nasal, vomer, palatine, inferior concha, and mandible. See the entire definition of Skull
Sodium: The major positive ion (cation) in fluid outside of cells. The chemical notation for sodium is Na+. When combined with chloride, the resulting substance is table salt. See the entire definition of Sodium
Spasm: A brief, automatic jerking movement. A muscle spasm can be quite painful, with the muscle clenching tightly. A spasm of the coronary artery can cause angina. Spasms in various types of tissue may be caused by stress, medication, over-exercise, or other factors.
Speech therapy: The treatment of speech and communication disorders. The approach used depends on the disorder. It may include physical exercises to strengthen the muscles used in speech (oral-motor work), speech drills to improve clarity, or sound production practice to improve articulation. See the entire definition of Speech therapy
Stroke : The sudden death of some brain cells due to a lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A stroke is also called a cerebrovascular accident or, for short, a CVA. See the entire definition of Stroke
Subarachnoid: Literally, beneath the arachnoid, the middle of three membranes that cover the central nervous system. In practice, subarachnoid usually refers to the space between the arachnoid and the pia mater, the innermost membrane surrounding the central nervous system. See the entire definition of Subarachnoid
Subarachnoid hemorrhage: Bleeding within the head into the space between two membranes that surround the brain. The bleeding is beneath the arachnoid membrane and just above the pia mater. (The arachnoid is the middle of three membranes around the brain while the pia mater is the innermost one.) See the entire definition of Subarachnoid hemorrhage
Substance: 1. Material with particular features, as a pressor substance. 2. The material that makes up an organ or structure. Also known in medicine as the substantia. 3. A psychoactive drug as, for example, in substance abuse.
Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office. See the entire definition of Surgery
Symptom: Any subjective evidence of disease. Anxiety, lower back pain, and fatigue are all symptoms. They are sensations only the patient can perceive. In contrast, a sign is objective evidence of disease. A bloody nose is a sign. It is evident to the patient, doctor, nurse and other observers.
Therapy: The treatment of disease . See the entire definition of Therapy
Thrombosis: The formation or presence of a blood clot in a blood vessel. The vessel may be any vein or artery as, for example, in a deep vein thrombosis or a coronary (artery) thrombosis. The clot itself is termed a thrombus. If the clot breaks loose and travels through the bloodstream, it is a thromboembolism. Thrombosis, thrombus, and the prefix thrombo- all come from the Greek thrombos meaning a lump or clump, or a curd or clot of milk. See entries also to: Cavernous sinus thrombosis; Renal vein thrombosis. And see: Deep Vein Thrombosis and Pulmonary Embolism.
TIA: See Transient ischemic attack.
Tissue plasminogen activator: (tPA) An enzyme that helps dissolve clots. tPA is made by the cells lining blood vessels and has also been made in the laboratory. It is systemic thrombolytic (clot-busting) agent and is used in the treatment of heart attack and stroke. Activase (alteplase) is a tissue plasminogen activator produced by recombinant DNA technology. Recombinant tPA is abbreviated r-tPA.
Tobacco: A South American herb, formally known as Nicotiana tabacum , whose leaves contain 2-8% nicotine and serve as the source of smoking and smokeless tobacco . See the entire definition of Tobacco
Tomography: The process for generating a tomogram , a two-dimensional image of a slice or section through a three-dimensional object. Tomography achieves this remarkable result by simply moving an x-ray source in one direction as the x-ray film is moved in the opposite direction during the exposure to sharpen structures in the focal plane, while structures in other planes appear blurred. The tomogram is the picture; the tomograph is the apparatus; and tomography is the process. See the entire definition of Tomography
tPA: See: Tissue plasminogen activator.
Trachea: A tube-like portion of the breathing or "respiratory" tract that connects the "voice box" (larynx) with the bronchial parts of the lungs. See the entire definition of Trachea
Trauma: Any injury , whether physically or emotionally inflicted. "Trauma" has both a medical and a psychiatric definition. Medically, "trauma" refers to a serious or critical bodily injury, wound, or shock . This definition is often associated with trauma medicine practiced in emergency rooms and represents a popular view of the term. In psychiatry , "trauma" has assumed a different meaning and refers to an experience that is emotionally painful, distressful, or shocking, which often results in lasting mental and physical effects. See the entire definition of Trauma
Tubes: The "tubes" are medically known as the Fallopian tubes. There are two Fallopian tubes, one on each side, which transport the egg from the ovary to the uterus (the womb). The Fallopian tubes have small hair-like projections called cilia on the cells of the lining. See the entire definition of Tubes
Ulceration: The process or fact of being eroded away, as by an ulcer.
Ultrasound: High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. Ultrasound is often used to examine a fetus during pregnancy. There is no convincing evidence for any danger from ultrasound during pregnancy.
Unconscious: 1. Interruption of awareness of oneself and one's surroundings, lack of the ability to notice or respond to stimuli in the environment. A person may become unconscious due to oxygen deprivation, shock, central nervous system depressants such as alcohol and drugs, or injury. 2. In psychology, that part of thought and emotion that happens outside everyday awareness.
Vascular: Relating to the blood vessels of the body. The blood vessels of the body, as a group, are referred to as the vascular system. See the entire definition of Vascular
Vasculitis: Plural: vasculitides. A general term for a group of diseases that feature inflammation of the blood vessels. Each of these diseases is defined by characteristic distributions of blood vessel involvement, patterns of organ involvement, and laboratory test abnormalities. The causes of these vasculitis diseases are usually not known, but immune system abnormality is a common feature. See the entire definition of Vasculitis
Vein: A blood vessel that carries blood low in oxygen content from the body back to the heart. The deoxygenated form of hemoglobin (deoxyhemoglobin) in venous blood makes it appear dark. Veins are part of the afferent wing of the circulatory system which returns blood to the heart. See the entire definition of Vein
Vertigo: Aside from being the name of a classic 1958 Alfred Hitchcock film (with Jimmy Stewart and Kim Novak), vertigo is a feeling that you are dizzily turning around or that things are dizzily turning about you. Vertigo is usually due to a problem with the inner ear. Vertigo can also be caused by vision problems. See the entire definition of Vertigo
Vessel: A tube in the body that carries fluids: blood vessels or lymph vessels.
Vital: Necessary to maintain life. Breathing is a vital function.
Voluntary: Done in accordance with the conscious will of the individual. The opposite of involuntary. See the entire definition of Voluntary
Warfarin : An anticoagulant drug (brand names: Coumarin, Panwarfin, Sofarin) taken to prevent the blood from clotting and to treat blood clots and overly thick blood. Warfarin is also used to reduce the risk of clots causing strokes or heart attacks . See the entire definition of Warfarin
X-ray: 1. High-energy radiation with waves shorter than those of visible light. X-rays possess the properties of penetrating most substances (to varying extents), of acting on a photographic film or plate (permitting radiography), and of causing a fluorescent screen to give off light (permitting fluoroscopy). In low doses X-rays are used for making images that help to diagnose disease, and in high doses to treat cancer . Formerly called a Roentgen ray. 2. An image obtained by means of X-rays. See the entire definition of X-ray
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