Skip Navigation U.S. Department of Health and Human Services
Agency for Healthcare Research Quality
Archive print banner

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to for current information.


Abdominal aortic aneurysm—A distended and weakened area in the wall of the abdominal aorta, more common in those who suffer from atherosclerosis.

Abdominal cavity—The part of the body between the bottom of the ribs and the top of the thighs, containing most of the digestive and urinary systems along with some reproductive organs.

Adenoidectomy—The surgical removal of the adenoid glands.

Angioplasty—The use of surgery to make a damaged blood vessel function properly again; may involve widening or reconstructing the blood vessel.

Aorta—The main artery in the body, carrying oxygenated blood from the heart to other arteries in the body.

Appendectomy—Surgical removal of the appendix to treat appendicitis.

Appendicitis—Inflammation of the appendix.

Appendix—Short, tubelike structure that branches off the large intestine; does not have any known function.

Arteriography—Roentgenography of arteries after injection of radiopaque material into the blood stream.

Artery—A large blood vessel that carries blood from the heart to tissues and organs in the body.

Arthroplasty—The surgical repair of a joint.

Biopsy—A procedure that involves obtaining a tissue specimen for microscopic analysis to establish a precise diagnosis.

Blood transfusion—The transfer of blood or any of its parts to a person who has lost blood due to an injury, disease, or operation.

Bone marrow—The fatty yellow or red tissue inside bones that is responsible for producing blood cells.

Bone marrow transplant—A surgical procedure in which defective or cancerous bone marrow is replaced with healthy marrow, either from the patient or a donor.

Bronchoscopy—An examination used for inspection of the interior of the tracheo-bronchial tree, performance of endobronchial diagnostic tests, taking of specimens for biopsy and culture and removal of foreign bodies.

Breech birth—Childbirth in which the baby is turned around in the uterus and emerges head-last instead of head-first.

Bypass—A surgical technique in which the flow of blood or another body fluid is redirected around a blockage.

Cardiovascular system—The heart and blood vessels that are responsible for circulating blood throughout the body.

Cardioverter/defibrillator—A device which delivers a measured electrical shock to arrest fibrillation of the heart (ventricle).

Catheter—A hollow, flexible tube inserted into the body to put in or take out fluid, or to open up or close blood vessels.

Catheterization—A technique in which a hollow, flexible tube is used to drain body fluids (such as urine), to introduce fluids into the body, or to examine or widen a narrowed vein or artery.

Cerebral aneurysm—A dilated and weakened portion of a cerebral blood vessel that is prone to rupture.

Cesarean section—An operation performed to remove a fetus by cutting into the uterus, usually through the abdominal wall.

Chemotherapy—The treatment of infections or cancer with drugs that act on disease-producing organisms or cancerous tissue; may also affect normal cells.

Circumcision—The surgical removal of the foreskin of the penis.

Cholecystectomy—The surgical removal of the gallbladder.

Colonoscopy—Investigation of the inside of the colon using a long, flexible fiberoptic tube.

Coronary—Describes structures that encircle another structure (such as the coronary arteries, which circle the heart); commonly used to refer to a coronary thrombosis or a heart attack.

Coronary arteries—The arteries that branch off from the aorta and supply oxygen-rich blood to the heart muscle.

Coronary artery bypass graft (CABG) surgery—An operation in which a piece of vein or artery is used to bypass a blockage in a coronary artery; performed to prevent myocardial infarction (heart attack) and relieve angina pectoris (chest pain due to reduced blood flow to heart muscles).

CT scanning—Computerized axial tomography, a procedure that uses X-rays and computers to create cross-sectional images of the body to diagnose and monitor disease.

Detoxification—Treatment given either to fight a person's dependence on alcohol or other drugs or to rid the body of a poisonous substance and its effects.

Echocardiogram—An image of the heart that is created by high-frequency (ultrasound) sound waves.

Electroencephalography—A procedure for recording the electrical impulses of brain activity.

Embolism—The blockage of a blood vessel by an embolus—something previously circulating in the blood (such as a blood clot, gas bubble, tissue, bacteria, bone marrow, cholesterol, fat, etc.).

Endocrine system—The system of glands that release their secretions (hormones) directly into the circulatory system.

Endoscopy—The visual inspection of any cavity of the body by means of an endoscope.

Enteral—A method of nutrient delivery where fluid is given directly into the gastrointestinal tract.

Enterostomy—Creation of an artificial external opening or fistula in the intestines.

Episiotomy—A surgical procedure in which an incision is made in the tissue between the vagina and anus to prevent tearing of this tissue during childbirth.

Excision—The surgical removal of diseased tissue.

Extracorporeal circulation—Diversion of blood flow through a circuit located outside the body but continuous with the bodily circulation.

Fallopian tube—Either of two long, slender ducts connecting a woman's uterus to her ovaries, where eggs are transported from the ovaries to the uterus and sperm may fertilize an egg.

Femoral hernia—A common type of groin hernia which occurs most often in obese females.

Femur—The bone located between the hip and the knee; the thighbone.

Fetal monitoring—The use of an instrument to record or listen to a fetus' heartbeat during pregnancy and labor.

Fetus—The term used to refer to an unborn child from 8 weeks after fertilization to birth.

Fibrillation—Rapid, inefficient contraction of muscle fibers of the heart caused by disruption of nerve impulses.

Forceps delivery—The use of an instrument that cups the baby's head (called an obstetric forceps) to help deliver a baby.

Foreign body—An object in an organ or body cavity that is not normally present.

Fracture—A bone break.

Gastrectomy—Surgical removal of all or part of the stomach.

Gastrointestinal tract—The part of the digestive system that includes the mouth, esophagus, stomach, and intestines.

Gastrostomy—The surgical creation of an opening in the abdominal wall into the stomach for drainage or a feeding tube.

Graft—Healthy tissue that is used to replace diseased or defective tissue.

Heart valve—The structure at each exit of the four chambers of the heart that allows blood to exit but not to flow back in.

Hemodialysis—A method used to treat kidney failure, in which blood is passed through a machine that purifies it and returns it to the body.

Hysterectomy—Surgical removal of the uterus.

Ileostomy—A surgical procedure in which the lower part of the small intestine (the ileum) is cut and brought to an opening in the abdominal wall, where feces can be passed out of the body.

Ileum—The lowest section of the small intestine, which attaches to the large intestine.

Induction of labor—The use of artificial means to start the process of childbirth.

Inguinal hernia—The bulging of a portion of the intestines or abdominal tissue into the muscles of the groin (the area just below the abdomen).

Inoculation—Introduction of material (usually a vaccine) into the tissues.

Intervertebral disks—Broad, flat cartilage structures containing a gel-like fluid that cushion and separate vertebrae.

Intubation—The passage of a tube into an organ or body structure; commonly used to refer to the passage of a tube down the windpipe for artificial respiration.

Kidney—One of two organs that are part of the urinary tract; responsible for filtering the blood and removing waste products and excess water as urine.

Laceration—A torn or ragged wound.

Laminectomy—A surgical procedure that removes part of a vertebra to relieve pressure on the spinal cord or a nerve branching from the spinal cord.

Laparoscope—A viewing instrument used to examine and treat disorders in the abdominal cavity; consists of a long tube with an eyepiece, a lens, and often a camera, which allows the image to be viewed on a monitor.

Laparoscopic cholecystectomy—Surgical removal of the gallbladder using a laparoscope.

Lesion—An abnormality of structure or function in the body.

Ligation—The process of closing a blood vessel or duct by tying it off.

Liver—The largest organ in the body, producing many essential chemicals and regulating the levels of most vital substances in the blood.

Lymphatic system—The tissues and organs (including the bone marrow, spleen, thymus and lymph nodes) that produce and store cells that fight infection and the network of vessels that carry lymph.

Mortality—The death rate, measured as the number of deaths per a certain population; may describe the population as a whole, or a specific group within a population (such as infant mortality or in-hospital mortality).

Musculoskeletal system—All the muscles, bones, and cartilage of the body collectively.

Myringotomy—A surgical opening in the eardrum that allows for drainage.

Nerve—A bundle of fibers that transmit electrical messages between the brain and areas of the body; these messages convey sensory or motor function information.

Obstetrics—A branch of medicine dealing with the care of women during pregnancy, childbirth, and the period during which they recover from childbirth.

Oophorectomy—The surgical removal of one or both ovaries; used to treat the growth of ovarian cysts or tumors.

Open heart surgery—Any operation in which the heart is stopped temporarily and a machine is used to take over its function of pumping blood throughout the body.

Ophthalmology—The area of medicine dealing with the eye.

Otologic surgical procedures—Surgery performed on the external, middle, or internal ear.

Ovaries—Two almond-shaped glands located at the opening of the fallopian tubes on both sides of the uterus; produce eggs and the sex hormones estrogen and progesterone.

Pacemaker—A small electronic device that is surgically implanted to stimulate the heart muscle to provide a normal heartbeat.

Parenteral—Not through the alimentary canal but rather by injection through some other route, as subcutaneous, intramuscular, intraorbital, intracapsular, intraspinal, intrasternal, intravenous, etc.

Percutaneous—Performed through the skin, as injection of radiopaque material in radiological examination or the removal of tissue for biopsy accomplished by a needle.

Pharynx—The throat; the tube connecting the back of the mouth and nose to the esophagus and windpipe.

Phototherapy—Treatment with light; for example, a newborn with jaundice may be put under light.

Physical therapy—The treatment of injuries or disorders using physical methods, such as exercise, massage, or the application of heat.

Pleura—The serous membranes covering the lungs (visceral pleura) and lining the inner aspect of the pleural cavity (parietal pleura).

Prophylactic—Anything used to prevent disease.

Psychological—Relating to the mind and the processes of the mind.

PTCA—Percutaneous transluminal coronary angioplasty, dilation of an occluded coronary artery (or arteries) by means of a balloon catheter to restore myocardial blood supply.

Rehabilitation—Treatment for an injury or illness aimed at restoring physical abilities.

Resection—Partial or complete surgical removal of a diseased organ or structure.

Respiration—The process by which oxygen is taken in and used by tissues in the body and carbon dioxide is released.

Respiratory system—The organs that carry out the process of respiration.

Retina—A membrane lining the inside of the back of the eye that contains light-sensitive nerve cells that convert focused light into nerve impulses, making vision possible.

Screening—The testing of an otherwise healthy person in order to diagnose disorders at an early stage.

Spleen—An organ located in the upper left abdomen behind the ribs that removes and destroys old red blood cells and helps fight infection.

Spinal tap—Another term for a lumbar puncture.

Swan-Ganz catheter—A special haemodynamic monitoring device (long thin catheter) that is introduced into a large vein (in the neck, chest or groin) and advanced through the right heart to the pulmonary artery.

Thoracentesis—A medical procedure that involves the removal of fluid from the chest cavity using a hollow bore needle.

Tonsillectomy—Surgical removal of the tonsils, usually to treat tonsillitis.

Tracheostomy—The surgical creation of an artificial airway in the trachea (windpipe) on the anterior surface of the neck.

Transplant—Transferring a healthy tissue or organ to replace a damaged tissue or organ; also refers to the tissue or organ transplanted.

Transurethral prostatectomy—Removal of cancerous tissue from the prostate gland using a resectoscope (a long, narrow instrument passed up the urethra), which allows the surgeon to simultaneously view the prostate and cut away the cancerous tissue.

Tubal ligation—A procedure in which the fallopian tubes are cut and tied off; usually a permanent form of sterilization.

Ultrasound scanning—An imaging procedure used to examine internal organs in which high-frequency sound waves are passed into the body, reflected back, and used to build an image.

Urethra—The tube by which urine is released from the bladder.

Uterus—The hollow female reproductive organ in which a fertilized egg is implanted and a fetus develops.

Vaccination—A form of immunization in which killed or weakened microorganisms are placed into the body, where antibodies against them are developed; if the same types of microorganisms enter the body again, they will be destroyed by the antibodies.

Vaccine—A preparation of weakened microorganisms given to create resistance to a certain disease.

Vacuum extraction—A technique used to facilitate childbirth using a suction device to help move the baby through the birth canal.

Valve—A structure that allows fluid flow in only one direction.

Vascular—Pertaining to blood vessels.

Vein—A blood vessel that carries blood toward the heart.

Ventilation—The process through which oxygen and carbon dioxide are exchanged between the lungs and the air; also refers to the use of a machine to carry out this process in someone who cannot breathe on his or her own.

Ventricle—A small cavity or chamber; there are four ventricles in the brain that circulate cerebrospinal fluid through it, and two in the heart that pump blood throughout the body.

Sources for Glossary

Young, T. American Medical Association medical glossary

Dark, G. On-line medical dictionary (

Return to Contents

For More Information

More information on HCUP data and the CCS can be obtained at

Additional descriptive statistics (national, regional, and for selected States) can be viewed through HCUPnet, a Web-based tool providing easy access to information on hospital stays. HCUPnet is available at

NIS data can be purchased for research through the National Technical Information Service (NTIS), U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161 (telephone: 1-800-553-6847 or 703-605-6000) or order online at Following is a list of products currently available:

  • Release 6, 1997 data (PB 2000-500006).
  • Release 5, 1996 data (PB 99-500480).
  • Release 4, 1995 data (PB 98-500440).
  • Release 3, 1994 data (PB 97-500433).
  • Release 2, 1993 data (PB 96-501325).
  • Release 1, 1988-1992 data (PB 95-503710).

Price for Release 1 is $322; price for Releases 2 through 6 is $160 per year. All prices may be higher for customers outside the United States, Canada, and Mexico.

Healthcare Cost and Utilization Project (HCUP)
Agency for Healthcare Research and Quality
Phone: 866-290-HCUP (4287), toll-free

Return to Contents

AHRQ Publication No. 01-0016
Current as of February 2001


The information on this page is archived and provided for reference purposes only.


AHRQ Advancing Excellence in Health Care