University of California San Francisco

    Medical Terms & Glossary

    Abdominal aorta
    Portion of the aorta within the abdominal cavity, extending from the diaphragm to the pelvis; its main branches supply the major vital organs, including the entire GI tract, liver, and kidneys.


    Abdominal aortic aneurysm
    Dilation (ballooning) greather than 50% of normal diameter of all three layers of the abdominal aorta, the body's largest artery. Most common true aneurysm of the artery; rupture results in life-threatening internal bleeding.


    Angina
    Chest pain caused by restricted blood flow causing reduced oxygen supply to the heart.


    Aneurysm
    A “ballooning” of a blood vessel, usually an artery; the result of plaque weakening the wall of an artery, then blood pressure causing the artery to balloon out and the artery wall to become dangerously thin.


    Angiography
    Test procedure whereby a special dye (or other contrast material) is introduced into blood vessels to better visualize disease, and the flow of blood; resulting images are called angiograms.


    Angioplasty
    Procedure whereby a balloon-tipped catheter is passed through a blockage in an artery, and inflated to compress the plaque build-up against the artery wall; thereby, reopening the narrowed artery.


    Anticoagulant
    Any substance, which inhibits clotting of the blood.


    Aorta
    Largest artery in the body originating at the heart’s left ventricle; carries oxygen-rich blood to body’s organs and tissue.


    Aortic insufficiency
    Inadequate closure of the aortic valve or an irregularity of the aortic root that allows blood to back through the valve.


    Aortic stenosis
    Aortic valve that doesn’t open all the way, inhibiting the flow of blood.


    Aortic valve
    Flap-like structure allowing blood flow from the left ventricle of the heart to the aorta.


    Arteriography
    A special x-ray technique using dye that is injected through a catheter inserted in an artery in the leg or arm.


    Arteriole
    The smallest branch of an artery that connects with the capillaries.


    Arteritis
    Inflammation of an artery.


    Artery
    A blood vessel carrying blood with oxygen and nutrients from the heart to the entire body.


    Atherectomy
    Procedure wherein a catheter with a device is used to clear away plaque blocking an artery.


    Atherosclerosis
    A progressive narrowing and hardening of the arteries; caused when plaques develop in the wall of arteries, due to the accumulation of cholesterol and other fats, and reduce blood flow.


    Atrium
    One of two upper chambers in the heart that receive blood. The right atria receives deoxygenated blood from the body and sends it through to the right ventricle and out to the lungs. The left ventricle receives oxygenated blood from the lungs sending it to the left ventricle then out through the aorta to the body.


    Balloon angioplasty
    Procedure wherein a catheter with a balloon at its tip is inserted into a blocked or narrowed artery. The balloon is expanded to widen the artery, increasing blood flow, and the catheter is then removed.


    Biobank
    A collection of blood and tissue samples used to identify biomarkers that can predict certain diseases or conditions.


    Blood clot
    A semi-solid gel-like material (a mix of blood cells, platelets, and fibrin); this natural product of blood coagulation is necessary to stem bleeding at a wound site.


    Blood pressure
    Pressure exerted by the pumping force of the heart, that causes blood flow in the arteries supplying  the heart and the rest  of the body. 


    Brain aneurysm
    A ballooning of an artery in the brain.


    Bruit
    (brew-ee) The sound blood makes when it rushes in a rough or turbulent manner through an artery partially blocked (narrowed) by plaque.


    Capillaries
    Smallest of all blood vessels, connects the smallest of all arteries and veins; semi-permeable, enabling blood with oxygen and nutrients to flow through the tissue, and allow waste products to return the venous blood for disposal.


    Cardiologist
    A physician who specializes in disorders of the heart.


    Cardiovascular disease
    Any disease of the blood vessels, primarily the arteries that supply the heart (coronary artery disease or CAD) and the entire body. 


    Carotid endarterectomy
    Most common surgical procedure for carotid artery blockages; carotid artery is exposed, blood is shunted around blocked area, plaque is removed, and the artery is shut. This procedure is closed by suturing.


    Cholesterol
    Necessary for metabolism, a fatty substance produced by the body and present in foods derived from animals; excessive levels contribute significantly to atherosclerosis.


    Claudication
    Pain in the muscles of the leg brought on when walking due to narrowed or blocked arteries that reduce blood flow and oxygen supplly to the leg that is relieved with rest. This is a symptom of Peripheral Artery Disease (PAD).


    Coagulation
    Process by which blood thickens to form a clot.


    Coronary artery disease (CAD)
    Usually caused by atherosclerosis, a progressive condition which reduces blood flow to the heart.


    CT
    Computed Axial Tomography – the CT or “CAT” scan produces a series of cross-sectional images of any part of the body.


    Deep vein thrombosis
    The formation of a blood clot within a vein, usually of the leg or pelvis; depending on clot size, it may obstruct blood flow leading to serious complications, including traveling to the lungs (Pulmonary Embolism).


    Diabetes
    A disorder of the body’s metabolism characterized by its inability to produce insulin (Type 1) or inability to utilize insulin (Type 2).


    Doppler and Duplex Tests
    During a Doppler ultrasound evaluation, a doctor or trained technician uses a special stethoscope to listen for changes in the sound of blood flow; Duplex imaging includes a Doppler evaluation but also uses sound waves bounced off red blood cells to create an image showing the size and shape of a blood vessel and the blood flowing through it.


    DSA
    Digital Subtraction Angiography – creates computer images after dye is inserted through a catheter.


    Embolectomy
    Surgical removal of a blood clot, which after circulating in the bloodstream became lodged in a blood vessel.


    Emboli/Embolus
    Circulating particles or blood clots that travel through the bloodstream until they become lodged in a smaller blood vessel.


    Embolic stroke
    Caused by a piece of plaque or clot floating in the bloodstream that lodges in one of the blood vessels that supplies the brain.


    Embolism
    An embolus that travels through the bloodstream, causing a sudden blockage in an artery or vein.


    Endovascular surgery
    Relatively new, less invasive surgery whereby surgeons enter the body through blood vessels rather than through a large incision.


    Femoral artery
    Main artery of the groin; supplies blood to lower extremities.


    Fusiform aneurysm
    An aneurysm bulging from all sides of an artery.


    Heart attack or “myocardial infarction”
    Occurs when reduced blood supply causes a portion of the heart muscle to die; often because a plaque buildup breaks down and a blood clot forms in a narrowed area of the artery.


    Heart failure
    A chronic, progressive condition in which the heart gradually loses its ability to ability to adequately pump blood to meet the body's needs for oxygen and nutrients. If left untreated, it will result in organ failure.


    Hematoma
    Typically a blood clot formed by blood which has leaked from a blood vessel.


    Hemorrhagic stroke
    When a blood vessel leaks, allowing blood to spill into nearby brain tissue, causing cell death.


    Hydrocephalus
    Enlarged ventricles (open chambers in the brain) caused by increased pressure inside the skull that blocks the cerebrospinal fluid which cushions the brain.


    Hypertension
    Technical term for “high blood pressure”; usually a persistent reading above 120/80 (systolic/diastolic) or higher.


    Hypoxia
    A reduction in the amount of oxygen reaching tissue, despite sufficient blood flow.


    Illiac arteries
    At the navel, the aorta splits into the two iliac arteries that transport blood into the pelvis and each leg.


    Ischemic stroke
    Most common type of stroke, usually when plaque buildup or blood clots block or severely narrow a blood vessel supplying or within the brain.


    Kidney failure
    Also known as “renal failure,” the kidney’s inability to adequately filter waste materials from the blood.


    Mitral valve prolapse
    Most common heart valve problem where the valve bulges slightly, allowing blood to back into the atrium when it closes.


    MRA
    Magnetic Resonance Angiography – uses a large cylinder (large enough for an entire body to pass through) to take pictures of blood vessels.


    Mycotic aneurysm
    A ballooned artery, usually saccular (see below), caused by an infected artery wall.


    Necrosis
    Death of tissue typically caused by injury, disease, or insufficient blood supply.


    Nuclear medicine imaging
    A diagnostic scan taken after a radioactive tracer is injected into a vein.


    Plaque
    Typically, a deposit of fat and cholesterol on the inner wall of a blood vessel that increases gradually over time, causing blockage of blood flow and/or emboli. Plaque build-up is that basic cause of atherosclerosis.


    Platelets
    Disk-shaped cells produced in the bone marrow and released into the blood; important for coagulation and repair of breaks in blood vessel walls.


    Pulmonary artery
    An artery which carries oxygen-depleted blood (an exception to the rule) from the right ventricle of the heart to the lungs.


    Pulmonary embolism
    The result of a circulating blood clot becoming lodged in a pulmonary artery.


    Pulmonary vein
    A vein which returns oxygen-rich blood (an exception to the rule) from the lungs to the left side of the heart.


    Renal arteries
    Branches of the abdominal aorta that carry oxygen-rich blood to the kidneys.


    Restenosis
    The reoccurrence of stenosis, a narrowing of a blood vessel leading to restricted blood flow. Restenosis due to scar tissue occurs in 30 to 50% of patients after they undergo angioplasty, stents, or bypass grafts.


    Saccular aneurysm
    A “bulge” on one side of an artery.


    Sepsis
    The presence of infection-causing organisms in the blood.


    Statins
    A class of drugs that reduce cholesterol in the blood.


    Stenosis
    The abnormal narrowing of a blood vessel leading to restricted blood flow, often caused by atherosclerosis or plaque buildup.


    Stent
    Small metal coil or mesh tube inserted into an artery to prevent the artery from re-narrowing (“restenosis”), usually following an angioplasty.


    Stroke
    Sudden loss of brain function due to an artery blockage or rupture depriving the brain of oxygen; often results from a buildup of plaque in the blood vessels.


    Superficial vein
    A vein lying close to the surface of the skin.


    Thoracic aorta
    The portion of the aorta which descends through the left chest cavity.


    Thrombus
    A blood clot originating inside and attached to a blood vessel wall; often obstructing blood flow.


    Thrombectomy
    Surgical removal of a thrombus.


    Thrombosis
    Formation or presence of aggregated platelets and clotted blood inside a blood vessel or heart cavity (“coronary thrombosis”).


    TIA
    Transient Ischemic Attack – a temporary episode caused by a clot, often called a "warning stroke", which lasts seconds to an hour, usually with no lasting damage. TIA's are sometimes referred to as mini-strokes. Symptoms may include: weakness, numbing, tingling or loss of feeling in face, arm or leg; trouble seeing or double vision; slurred speech or problems understanding others; sudden, severe headache; dizziness or spinning feeling; lost of balance; blackouts.


    Translational Research
    The new definition of translational research is performed by clinician-scientists and emphasizes "Bedside to Bench and Back to Bedside," often referred to as Patient-Oriented Research. This is a contrast to "Bench to Bedside" Disease-Oriented Research, often performed by basic scientists. Clinician-scientists make novel observations about the nature and progression of disease. By collaborating with basic scientists, who provide new tools, they make relevant discoveries that can improve patient treatments and outcomes.

    Triglycerides
    A large portion of the fatty substances found in the blood that is either ingested or produced in the liver. As with cholesterol, excessive levels contribute to atherosclerosis.


    Ultrasound
    A test using sound waves to form an image of an area or blood vessel.


    Valve
    A flap-like structure which by opening and closing allows a fluid to move in one direction only; valves help regulate blood flow.


    Varicose vein
    A vein which is swollen and/or twisted; most often seen in the superficial veins of the leg.


    Vascular disease
    Any disease of the circulatory system. Vascular refers to veins and arteries.


    Vascular surgeon
    A physician who specializes in the surgical treatment of blood vessels.


    Vein
    A blood vessel (except pulmonary veins) through which oxygen-depleted blood returns to the heart.


    Vena cava
    The large vein in the abdomen and chest, which returns oxygen-depleted blood to the heart.


    Venous stasis
    Abnormal reduction of blood flow through veins, especially those of the lower extremities.


    Ventricle
    One of two lower chambers in the heart, which either circulates blood to the lungs (right ventricle) for oxygen replenishment, or to the rest of the body (left ventricle) via the arteries.