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February 10, 2012

Pulmonary Embolism (Blood Clot in the Lung) Glossary of Terms

The following are health and medical definitions of terms that appear in the Pulmonary Embolism (Blood Clot in the Lung) article.

Abdominal: Relating to the abdomen, the belly, that part of the body that contains all of the structures between the chest and the pelvis. The abdomen is separated anatomically from the chest by the diaphragm, the powerful muscle spanning the body cavity below the lungs.
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Abdominal cavity: The cavity within the abdomen, the space between the abdominal wall and the spine.
See the entire definition of Abdominal cavity

Alveoli: The plural of alveolus. The alveoli are tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place.

Ambulatory: Able to ambulate, to walk about, not bed-ridden or hospitalized.

Amniotic fluid: The fluid bathing the fetus and serving as a shock absorber.

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."
See the entire definition of Aneurysm

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.

Aortic: Pertaining to the aorta, the largest artery in the body.
See the entire definition of Aortic

Aortic aneurysm: An outpouching (a local widening) of the largest artery in the body, the aorta, involving that vessel in its course above the diaphragm (thoracic aortic aneurysm) or, more commonly, below the diaphragm (abdominal aortic aneurysm). The diagnosis of an aortic aneurysm can be straight forward or difficult. Around 1900 the eminent physician William Osler said: "There is no disease more conducive to clinical humility than aneurysm of the aorta." At the area of the aneurysm, there is typically a bulge and the wall is weakened and may rupture. Because of the volume of blood flowing under relatively high pressure through the aorta, a ruptured aneurysm of the aorta is a catastrophe.
See the entire definition of Aortic aneurysm

Arms: An appendage in anatomy and in clinical trials. See: Arm.

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

Birth control: Birth control is the use of any practices, methods, or devices to prevent pregnancy from occurring in a sexually active woman. Also referred to as family planning, pregnancy prevention, fertility control, or contraception; birth control methods are designed either to prevent fertilization of an egg or implantation of a fertilized egg in the uterus.
See the entire definition of Birth control

Blood clot: Blood that has been converted from a liquid to a solid state. Also called a thrombus.
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Blood clots: Blood that has been converted from a liquid to a solid state. Also called a thrombus.
See the entire definition of Blood clots

Blood count: The calculated number of white or red blood cells (WBCs or RBCs) in a cubic millimeter of blood.

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 urea nitrogen: Abbreviated BUN. A measure primarily of the urea level in blood. Urea is cleared by the kidney. Diseases that compromise the function of the kidney frequently lead to an increased BUN.

Bloody sputum: Coughed up blood or bloody mucus. Bloody sputum can be caused by infection in the lungs and airways, such as acute bronchitis or pneumonia and by cancer. Whenever bloody sputum is present and cannot be attributed to a curable infectious condition, a complete lung evaluation is warranted, including bronchoscopy, to be certain cancer is not present. Also known as hemoptysis.

Breathing: The process of respiration, during which air is inhaled into the lungs through the mouth or nose due to muscle contraction, and then exhaled due to muscle relaxation.

Bridge: A set of one or more false teeth supported by a metal framework, used to replace one or more missing teeth.
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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

Capillaries: Capillaries are the smallest of blood vessels. They serve to distribute oxygenated blood from arteries to the tissues of the body and to feed deoxygenated blood from the tissues back into the veins. The capillaries are thus a central component in the circulatory system, essentially between the arteries and the veins. When pink areas of skin are compressed, this causes blanching because blood is pressed out of the capillaries. The blood is the fluid in the body that contains, among other elements, the red blood cells (erythrocytes) that carry the oxygen and give the blood its red color.

Carbon dioxide: A gas which is the byproduct of cellular metabolism and which collects in the tissues, is cleared from the tissues by the blood within the veins, is carried by the hemoglobin in the red blood cells, and removed from the body via the lungs in the exhaled air. Abbreviated CO2.

Cardiac: Having to do with the heart.

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

CBC: A commonly used abbreviation in medicine that stands for complete blood count, a set values of the cellular (formed elements) of blood. These measurements are generally determined by specially designed machines that analyze the different components of blood in less than a minute.
See the entire definition of CBC

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

Chest pain: There are many causes of chest pain. One is angina which results from inadequate oxygen supply to the heart muscle. Angina can be caused by coronary artery disease or spasm of the coronary arteries. Chest pain can also be due to a heart attack (coronary occlusion) and other important diseases such as, for example, dissection of the aorta and a pulmonary embolism. Do not try to ignore chest pain and "work (or play) though it." Chest pain is a warning to seek medical attention.

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Chest X-ray: Commonly used to detect abnormalities in the lungs, but can also detect abnormalities in the heart, aorta, and the bones of the thoracic area. Metallic objects, such as jewelry are removed from the chest and neck areas for a chest x-ray to avoid interference with x-ray penetration and improve accuracy of the interpretation.

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.

Circulatory: Having to do with the circulation, the movement of fluid in a regular or circuitous course. Although the adjective "circulatory" need not necessarily refer to the circulation of the blood, for all practical purposes today it does. A circulatory problem is taken usually to be a problem with the blood circulation, for example with heart failure.

Circulatory system: The system that moves blood throughout the body. The circulatory system is composed of the heart, arteries, capillaries, and veins. This remarkable system transports oxygenated blood from the lungs and heart throughout the body via the arteries. The blood goes through the capillaries which are situated between the arteries and veins. And the blood that has been depleted of oxygen by the body is then returned to the lungs and heart via the veins.

Collapsed lung: Failure of full expansion of a once fully expanded lung. Medically called atelectasis. The word comes from the Greek "a-" (without) + "telos" (complete) + "rectasis" (expansion) = without complete expansion.

Complete blood count: A set values of the cellular (formed elements) of blood. These measurements are generally determined by specially designed machines that analyze the different components of blood in less than a minute.
See the entire definition of Complete blood count

Compression: 1. The act of pressing together. As in a compression fracture, nerve compression, or spinal cord compression.
2. To shorten in time. In embryology, there may be compression of development with some stages even omitted.

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

Contrast: Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.

Cough: A rapid expulsion of air from the lungs typically in order to clear the lung airways of fluids, mucus, or material. Also called tussis.

Creatinine: A chemical waste molecule that is generated from muscle metabolism. Creatinine is produced from creatine, a molecule of major importance for energy production in muscles. Approximately 2% of the body's creatine is converted to creatinine every day. Creatinine is transported through the bloodstream to the kidneys. The kidneys filter out most of the creatinine and dispose of it in the urine.
See the entire definition of Creatinine

Creatinine blood test: A test that helps determine whether the kidneys are functioning normally. The kidneys maintain the blood creatinine in a normal range. Creatinine has been found to be a fairly reliable indicator of kidney function.
See the entire definition of Creatinine blood test

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

Cyanotic: Showing cyanosis (bluish discoloration of the skin and mucous membranes due to not enough oxygen in the blood). See: Cyanosis.

D-dimer: A fragment produced during the degradation of a clot. The D here stands for domain. Dimer indicates two identical units, in this case two identical domains. D-dimer result from complete breakdown of the clot. Monoclonal antibody to the D-dimer fragment provide the basis for the main methods of detecting it. The presence of D-dimers in the blood is a reliable clue that clotting has begun. Sometimes written d-dimer or D-Dimer. Pronounced deemer.

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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

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.
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Dissection: The process of cutting apart or separating tissue as, for example, in the study of anatomy or in the course of a surgical procedure.

ECG: Abbreviation for electrocardiogram or EKG. The K is from "kardio" (in German).

Echocardiography: Echocardiography is a diagnostic test which uses ultrasound waves to make images of the heart chambers, valves and surrounding structures. It can measure cardiac output and is a sensitive test for inflammation around the heart (pericarditis). It can also be used to detect abnormal anatomy or infections of the heart valves.

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

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

Embolus: 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 Embolus

Enoxaparin: A low-molecular-weight version of heparin which acts like heparin as an anticoagulant (anti-clotting) medication. Enoxaparin is used to prevent thromboembolic complications (clots that travel from their site of origin through the blood stream to clog up another vessel). Enoxaparin is also used in the early treatment of blood clots in the lungs (pulmonary embolisms).

Essential: 1. Something that cannot be done without.
2. Required in the diet, because the body cannot make it. As in an essential amino acid or an essential fatty acid.
3. Idiopathic. As in essential hypertension. "Essential" is a hallowed term meaning "We don't know the cause."

Estrogen: Estrogen is a female hormone produced by the ovaries. Estrogen deficiency can lead to osteoporosis.
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Extremity: The extremities in medical language are not freezing cold or scorching heat but rather the uttermost parts of the body. The extremities are simply the hands and feet.
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Femur: The femur is the bone in the leg that extends from the hip to the knee.
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Finger stick: A procedure in which a finger is pricked with a lancet to obtain a small quantity of capillary blood for testing. Also called a finger prick.

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Genetic: Having to do with genes and genetic information.

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.
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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

Heart muscle: A type of muscle with unique features only found in the heart. The heart muscle, or cardiac muscle, is medically called the myocardium ("myo-" being the prefix denoting muscle).

Heart rate: The number of heart beats per unit time, usually per minute. The heart rate is based on the number of contractions of the ventricles (the lower chambers of the heart). The heart rate may be too fast (tachycardia) or too slow (bradycardia). The pulse is bulge of an artery from the wave of blood coursing through the blood vessel as a result of the heart beat. The pulse is often taken at the wrist to estimate the heart rate.

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).

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.

Infarct: An area of tissue death due to a local lack of oxygen.
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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.
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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.
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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.

International normalized ratio: A system, commonly called the INR, established by the World Health Organization (WHO) and the International Committee on Thrombosis and Hemostasis for reporting the results of blood coagulation (clotting) tests. All results are standardized using the international sensitivity index for the particular thromboplastin reagent and instrument combination utilized to perform the test.
See the entire definition of International normalized ratio

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.


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Laboratory: A place for doing tests and research procedures and preparing chemicals, etc. Although "laboratory" looks very like the Latin "laboratorium" (a place to labor, a work place), the word "laboratory" came from the Latin "elaborare" (to work out, as a problem, and with great pains), as evidenced by the Old English spelling "elaboratory" designating "a place where learned effort was applied to the solution of scientific problems."

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.
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Lethal: Deadly, fatal, capable of causing death, death-dealing. The word "lethal" comes from the Latin "letum" meaning "death or destruction."

Lower leg: The lower leg is the bottom segment of the leg: the part below the knee.
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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.

Membrane: A very thin layer of tissue that covers a surface.

Mortality: A fatal outcome or, in one word, death. The word "mortality" is derived from "mortal" which came from the Latin "mors" (death). The opposite of mortality is, of course, immortality. Mortality is also quite distinct from morbidity (illness).
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Mortality rate: A death rate. There are a number of different types of mortality rates as, for examples, the following:

  • The fetal mortality rate: The ratio of fetal deaths to the sum of the births (the live births + the fetal deaths) in that year.
  • The infant mortality rate: The number of children dying under a year of age divided by the number of live births that year.
  • The maternal mortality rate: The number of maternal deaths related to childbearing divided by the number of live births (or by the number of live births + fetal deaths) in that year.

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Mouth: 1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral.

Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."

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.

Nitrogen: Element number 7, a colorless, odorless, tasteless gas that is biologically important. Nitrogen is a constituent of protein and nucleic acids and is present in all living cells. Nitrogen does not support respiration and is fatal if breathed alone, because of the lack of oxygen. Nitrogen is soluble in the blood and body fluids and, when released as bubbles of gas, can have serious or even fatal consequences.
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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.
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Outpatient: A patient who is not an inpatient (not hospitalized) but instead is cared for elsewhere -- as in a doctor's office, clinic, or day surgery center. The term outpatient dates back at least to 1715. Outpatient care today is also called ambulatory care.

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.
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Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors.
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Pleura: The thin covering that protects and cushions the lungs. The pleura is made up of two layers of tissue that are separated by a small amount of fluid.

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Pleurisy: Inflammation of the pleura, the linings surrounding the lungs. There are two layers of pleura; one covering the lung and the other covering the inner wall of the chest. These two layers are lubricated by pleural fluid. Pleurisy is frequently associated with a pleural effusion (the accumulation of extra fluid in the space between the two layers of pleura). Pleurisy causes a stabbing pain in the chest aggravated by breathing, chest tenderness, cough, and shortness of breath. Pleurisy can be caused by many conditions including infections, collagen vascular diseases (such as lupus and rheumatoid arthritis), cancers (such as metastatic lung cancer or breast cancer), tumors of the pleura, heart failure, lung embolism (blood clot in a vessel to the lungs), obstruction of lymph channels, trauma (rib fractures or injury from instruments in the chest from an operation or car accident), certain drugs (such as Hydralazine, Procan, and Dilantin), abdominal processes (such as pancreatitis, cirrhosis of the liver) and lung infarction (lung tissue death due to lack of oxygen from poor blood supply).
See the entire definition of Pleurisy

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.

Pneumothorax: Free air in the chest outside the lung.
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Poison: Any substance that can cause severe distress or death if ingested, breathed in, or absorbed through the skin. Many substances that normally cause no problems, including water and most vitamins, can be poisonous if taken in too large of a quantity. Poison treatment depends on the substance: if there are treatment instructions on the substance's container and you are sure it contained no other item, follow those directions immediately. Always contact your nearest Poison Control Center if you are concerned about possible poison ingestion.

Polycythemia: Too many red blood cells. The opposite of anemia. polycythemia formally exists when the hemoglobin, red blood cell (RBC) count, and total RBC volume are all above normal.

Pregnancy: The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long.
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Pregnant: The state of carrying a developing fetus within the body.
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Probability: The likelihood that something will happen. For example, a probability of less than .05 indicates that the probability of something occurring by chance alone is less than 5 in 100, or 5 percent. This level of probability is usually taken as the level of biologic significance, so a higher incidence may be considered meaningful. The abbreviation for probability is P.

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.
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Prophylaxis: A measure taken for the prevention of a disease or condition.
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Prothrombin: A coagulation (clotting) factor that is needed for the normal clotting of blood. A cascade of biochemical events leads to the formation of the final clot. In this cascade, prothrombin is a precursor to thrombin.
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Prothrombin time: A clotting test, the prothrombin time is done to test the integrity of part of the clotting scheme. The prothrombin time is commonly used as a method of monitoring the accuracy of blood thinning treatment (anticoagulation) with warfarin (Coumadin). Familiarly called the "pro time," the test is the time needed for clot formation after a substance called thromboplastin (+ calcium) has been added to plasma.
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Pulmonary: Having to do with the lungs. (The word comes from the Latin pulmo for lung).

Pulmonary artery: One of the two vessels which are formed as terminal branches of the pulmonary trunk and convey unaerated blood to the lungs. The two pulmonary arteries differ in length and anatomy.
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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.)
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Pulmonary embolus: A blood clot that has passed into and occluded the lung's pulmonary artery. An embolus causes an embolism. In this case, the embolus, a clot or foreign material, has been carried through the blood into the pulmonary artery or one of its branches, plugging the vessel.

Radiation: 1. Rays of energy. Gamma rays and X-rays are two of the types of energy waves often used in medicine. 2. The use of energy waves to diagnose or treat disease. See also: Irradiation.

Radiologist: A physician specialized in radiology, the branch of medicine that uses ionizing and nonionizing radiation for the diagnosis and treatment of disease.
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Red blood cells: The blood cells that carry oxygen. Red cells contain hemoglobin and it is the hemoglobin which permits them to transport oxygen (and carbon dioxide). Hemoglobin, aside from being a transport molecule, is a pigment. It gives the cells their red color (and their name).
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Regimen: With the accent on the first syllable (reg as in Reggie Jackson), a regimen is a plan, a regulated course such as a diet, exercise or treatment, designed to give a good result. A low-salt diet is a regimen.

Respiratory: Having to do with respiration, the exchange of oxygen and carbon dioxide. From the Latin re- (again) + spirare (to breathe) = to breathe again.

Respiratory rate: The number of breaths per minute or, more formally, the number of movements indicative of inspiration and expiration per unit time. In practice, the respiratory rate is usually determined by counting the number of times the chest rises or falls per minute. By whatever means, the aim is to determine if the respirations are normal, abnormally fast (tachypnea), abnormally slow (bradypnea), or nonexistent (apnea).

Right heart: The heart is composed functionally of two hearts - the right heart and the left heart. The right heart consists of the right atrium which receives deoxygenated blood from the body and the right ventricle which pumps it to the lungs. The right heart is a low pressure system.

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.
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Shock: In medicine, shock is a critical condition brought on by a sudden drop in blood flow through the body. There is failure of the circulatory system to maintain adequate blood flow. This sharply curtails the delivery of oxygen and nutrients to vital organs. It also compromises the kidney and so curtails the removal of wastes from the body. Shock can be due to a number of different mechanisms including not enough blood volume (hypovolemic shock) and not enough output of blood by the heart (cardiogenic shock). The signs and symptoms of shock include low blood pressure (hypotension), overbreathing (hyperventilation), a weak rapid pulse, cold clammy grayish-bluish (cyanotic) skin, decreased urine flow (oliguria), and mental changes (a sense of great anxiety and foreboding, confusion and, sometimes, combativeness).
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Shortness of breath: Difficulty in breathing. Medically referred to as dyspnea. Shortness of breath can be caused by respiratory (breathing passages and lungs) or circulatory (heart and blood vessels) conditions. See also dyspnea.

Sinus: 1. An air-filled cavity in a dense portion of a skull bone. The sinuses decrease the weight of the skull. The sinuses are formed in four right-left pairs. The frontal sinuses are positioned behind the forehead, while the maxillary sinuses are behind the cheeks. The sphenoid and ethmoid sinuses are deeper in the skull behind the eyes and maxillary sinuses. The sinuses are lined by mucous-secreting cells. Air enters the sinuses through small opening in bone called ostia. If an ostium is blocked, air cannot pass into the sinus and likewise mucous cannot drain out. See also: Sinusitis.
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Sinus tachycardia: A fast heartbeat (tachycardia) because of rapid firing of the sinoatrial (sinus) node.
See the entire definition of Sinus tachycardia

Sputum: The mucus and other matter brought up from the lungs, bronchi, and trachea that one may cough up and spit out or swallow. The word "sputum" is borrowed directly from the Latin "to spit." Called also expectoration.

Stasis: Stasis refers to a stoppage or slowdown in the flow of blood (or other body fluid such as lymph).
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Stethoscope: An instrument used to transmit low-volume sounds such as the heartbeat (or intestinal, venous, or fetal sounds) to the ear of the listener. A stethoscope may consist of two earpieces connected by means of flexible tubing to a diaphragm placed against the skin of the patient.
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Strain: 1. An injury to a tendon or muscle resulting from overuse or trauma. 2. A hereditary tendency that originated from a common ancestor. 3. To exert maximum effort. 4. To filter.

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.
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Tachycardia: A rapid heart rate, usually defined as greater than 100 beats per minute. The tachycardias include sinus tachycardia, paroxysmal atrial tachycardia (PAT), and ventricular tachycardia.
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Therapy: The treatment of disease.
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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.

Thrombus: A blood clot in a blood vessel or within the heart. From the Greek thrombos meaning a lump or clump, or a curd or clot of milk.

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.

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.

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

Trimester: The nine months of pregnancy is traditionally divided into three trimesters: distinct periods of roughly three months in which different phases of fetal development take place.
See the entire definition of Trimester

Tumor: An abnormal mass of tissue. Tumors are a classic sign of inflammation, and can be benign or malignant (cancerous). There are dozens of different types of tumors. Their names usually reflect the kind of tissue they arise in, and may also tell you something about their shape or how they grow. For example, a medulloblastoma is a tumor that arises from embryonic cells (a blastoma) in the inner part of the brain (the medulla). Diagnosis depends on the type and location of the tumor. Tumor marker tests and imaging may be used; some tumors can be seen (for example, tumors on the exterior of the skin) or felt (palpated with the hands).
See the entire definition of Tumor

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.

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Urea: A nitrogen-containing substance normally cleared from the blood by the kidney into the urine. Diseases that compromise the function of the kidney often lead to increased blood levels of urea, as measured by the blood urea nitrogen (BUN) test.
See the entire definition of Urea

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

Vessel: A tube in the body that carries fluids: blood vessels or lymph vessels.

Vital: Necessary to maintain life. Breathing is a vital function.

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.

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Pulmonary Embolism (Blood Clot in the Lung)

How does the heart work?

The heart is a two stage electric pump whose job it is to circulate blood through the body. There is a group of cells that serve as an automatic pacemaker located in the atrium that generates an electrical current that spreads to the heart muscle cells to generate a coordinated squeeze, so that the pump can function.

The heart has four chambers, the right and left atria (singular= atrium) and the right and left ventricles. The right side of the heart pumps blood to the lungs while the left side pumps it to the rest of the body.

Blood from the body is collected in the right atrium and is pushed into the right ventricle with a small beat of the upper chamber of the heart. The right ventricle then pumps the blood to the lungs to pick up oxygen. They oxygen-rich blood returns to the left atrium where the small atrial beat pushes it to the left ventricle. The left ventricle is much thicker than the right because it needs t...

Read the Abnormal Heart Rhythms (Heart Rhythm Disorders) article »







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