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CA-125 test - A blood test to detect an elevated level of a protein antigen called CA-125 (cancer antigen 125), which may indicate the presence of ovarian cancer, among other disorders. This test is often used to follow women who have already been diagnosed with ovarian cancer, to monitor their status after treatment.
Calcification - the gathering of small deposits of calcium in the breast tissue, usually found by mammography.
Calcitonin - a hormone secreted by the thyroid gland which controls the levels of calcium and phosphorous in the blood by inhibiting the breakdown of bone tissue.
Calcium - mineral that gives strength to bones and teeth and has an important role in muscle contraction, blood clotting, and nerve function.
Calcium channel blocker (or calcium blocker) - a medication that lowers blood pressure.
Calculi - stones or solid lumps such as gallstones.
Calluses - thick, hardened areas of the skin, usually on the foot, caused by friction or pressure.
CAM (Complementary and Alternative Medicine) - a group of nonconventional approaches to healing, beyond traditional medicine. Complementary medicine is any form of therapy used in combination with other alternative treatments or standard/conventional medicine. Alternative medicine is used alone, without recommended standard treatment. Examples of CAM include chiropractic medicine, massage therapy, yoga, acupuncture, Eastern medicine, and imagery.
Campylobacter pylori - previous name for the bacterium that causes stomach ulcers; it is now referred to as Helicobacter pylori, or H. pylori.
Cancellous tissue - the sponge-like tissue inside bones.
Cancer - a disease in which abnormal cells divide without control and can invade nearby tissues or spread through the bloodstream and lymphatic system to other parts of the body.
Candidiasis (also called yeast infection) - a skin infection caused by yeast that can occur in the skin folds, navel, vagina, penis, mouth, and nail beds.
Capillaries - tiny blood vessels connecting arteries and veins that distribute oxygen-rich blood to the body.
Capsular contracture - the most common complication of breast reconstruction surgery; when the scar tissue around a breast implant begins to shrink and tighten. This can cause pain and distortion of the breast.
Capsule - a layer of membrane-like tissue surrounding a joint, organ, tumor, or other structure.
Captioning - text display of spoken words presented on a television or a movie screen that allows a hearing-impaired viewer to follow the dialogue and the action of a program simultaneously.
Carbohydrates - one of the three main classes of food and a source of energy. Carbohydrates are the sugars and starches found in breads, cereals, fruits, and vegetables, which, during digestion, are changed into a simple sugar called glucose. Glucose is stored in the liver until cells need it for energy.
carbon monoxide (CO) - a colorless, odorless gas which can be created whenever a fuel (such as wood, gasoline, coal, natural gas, or kerosene) is burning.
Carbuncles - a type of skin infection that involves a cluster of hair follicles; usually caused by a staph infection.
Carcinogen - a substance that is known to cause cancer.
Carcinoma (also called cancer) - a disease in which abnormal cells divide without control and can invade nearby tissues or spread through the bloodstream and lymphatic system to other parts of the body.
Carcinoma in situ - cancer that is confined to the cells in which it first developed and has not invaded the surrounding tissues (metastasized).
Cardiac - pertaining to the heart.
Cardiac arrest - the sudden loss of heart function. It may occur when the heart beats so fast or so slowly that blood cannot be pumped to the body.
Cardiac catheterization - a diagnostic procedure in which a tiny, hollow tube (catheter) is advanced from a vessel in the groin through the aorta into the heart in order to assess the heart and blood vessels.
Cardiac output - total amount of blood being pumped by the heart over a particular period of time.
Cardiology - the clinical study and practice of treating the heart.
Cardiomyopathy - a disease of the heart muscle that causes it to lose its pumping strength.
Cardiopulmonary resuscitation (CPR) - an emergency life-saving method in which artificial respirations and chest compressions are used to restart the heart and lungs.
Cardiovascular (CV) - pertaining to the heart and blood vessel (circulatory) system.
Cardioversion - the procedure of applying electrical shock to the chest to change an abnormal heartbeat into a normal one.
Caregiver - someone who provides assistance, generally in the home environment, to an aging parent, spouse, other relative, or unrelated person, or to an ill or disabled person of any age. A caregiver can be a family member, friend, volunteer, or paid professional.
Carotid artery - the major artery in the neck that supplies blood to the brain.
Carpal tunnel syndrome - a condition in which the median nerve is compressed as it passes through the carpal tunnel in the wrist, a narrow confined space. Since the median nerve provides sensory and motor functions to the thumb and three middle fingers, many symptoms may result.
Carpenter syndrome - A genetic birth defect that typically includes traits such as abnormally short fingers, webbed toes, extra toes, underdeveloped jaw, highly arched palate, widely spaced eyes, and/or low-set, deformed ears. Many patients with Carpenter syndrome also have heart defects.
Cartilage - a smooth material that covers bone ends of a joint to cushion the bone and allow the joint to move easily without pain.
Cast - a device that holds a broken bone in place as it heals, prevents, or decreases muscle contractures, or provides immobilization, especially after surgery. Casts immobilize the joint above and the joint below the area that is to be kept straight and without motion.
Cataract - a change in the structure of the crystalline lens that causes blurred vision.
Cathartics - laxatives.
Catheter - a thin, flexible tube that carries fluids into or out of the body.
Cavernous hemangioma - a raised, red or purple mark in the skin, made up of enlarged blood vessels.
Cecostomy - tube that goes through the skin into the beginning of the large intestine to remove gas or feces; it is a short-term way to protect part of the colon while it heals after surgery.
Cecum - beginning of the large intestine; it is connected to the lower part of the small intestine, called the ileum.
Celiac disease (also called celiac sprue or gluten sensitive enteropathy) - a condition in which the ability to absorb nutrients in the small intestine is decreased because of damage to the lining of the small intestine. The damage is caused by a sensitivity to gluten, a wheat protein. Individuals with this disease must avoid gluten-containing grains, which include all forms of wheat, oats, barley, and rye.
Cellular pathology (also called cytopathology) - the study of cellular alterations in disease.
Cellulitis - a bacterial infection of the skin that is characterized by swelling and tenderness.
Central auditory processing disorder - inability of individuals with normal hearing and intelligence to differentiate, recognize, or understand sounds.
Central nervous system - the brain and the spinal cord.
Cephalohematoma - an area of bleeding underneath the scalp of a newborn that appears as a raised lump on the baby's head.
Cerebellum - a large structure consisting of two halves (hemispheres) located in the lower part of the brain; responsible for the coordination of movement and balance.
Cerebral embolism - a blockage in an artery in the brain caused by a blood clot. A cerebral embolism can cause an ischemic stroke.
Cerebral hemorrhage - bleeding in the brain caused by the rupture of a blood vessel in the brain. Cerebral hemorrhage can cause a hemorrhagic stroke.
Cerebral spinal fluid analysis (also called spinal tap or lumbar puncture) - a procedure used to make an evaluation or diagnosis by examining the fluid withdrawn from the spinal column.
Cerebral thrombosis - a blockage of an artery in the brain caused by a small particle other than a blood clot. A cerebral thrombosis can cause an ischemic stroke.
Cerebrovascular - pertaining to blood vessels in the brain.
Cerebrovascular accident - apoplexy or stroke; a blockage of the blood supply to the brain.
Cerebrovascular occlusion - an obstruction in a blood vessel in the brain.
Cerebrum - consists of two parts (lobes), left and right, which form the largest and most developed part of the brain; initiation and coordination of all voluntary movement take place within the cerebrum. The basal ganglia are located immediately below the cerebrum.
Cervical dysplasia - condition in which cells in the cervix have undergone precancerous changes, as detected by a Pap test; treatment can prevent it from progressing to cervical cancer.
Cervical intraepithelial neoplasia (CIN) - term used to classify the degree of precancerous changes in cells of the cervix in a condition called cervical dysplasia.
Cervical spine - the area of the spinal cord located in the neck; it consists of the first seven vertebrae (bones) of the spine.
Cervicitis - an irritation of the cervix by a number of different organisms. Cervicitis is generally classified as either acute or chronic.
Cervix - the lower, narrow part of the uterus (womb) located between the bladder and the rectum. It forms a canal that opens into the vagina, which leads to the outside of the body.
Cesarean delivery (also called C-section) - surgical procedure to deliver a baby through an incision in the lower abdomen and uterus.
CHAMPUS - the Civilian Health and Medical Program for Uniformed Services.
Chemical burns - burns caused by strong acids or alkalies coming into contact with the skin and/or eyes.
Chemical peels - a procedure often used to minimize sun-damaged skin, irregular pigment, and superficial scars. The top layer of skin is removed with a chemical application to the skin. By removing the top layer, the skin regenerates, often improving the skin's appearance.
Chemosensory disorders - disorders or diseases of smell or taste.
Chemotherapy - a type of treatment to destroy cancer cells with drugs.
Chickenpox - a highly infectious viral disease, usually associated with childhood. By adulthood, more than 95 percent of Americans have had chickenpox. The disease is caused by the varicella-zoster virus (VZV). Transmission occurs from person-to-person by direct contact or through the air.
Child safety seat - special seats for infants and toddlers that are secured in a vehicle with seat belts or special anchors to increase the safety of the child in the event of a crash.
Chlamydial infection - very common sexually transmitted disease or urinary tract infection caused by a bacteria-like organism in the urethra and reproductive system.
Chlorhydria (also called hyperchlorhydria) - a condition in which too much hydrochloric acid is produced in the stomach.
Cholangiography - series of X-rays of the bile ducts.
Cholangitis - irritated or infected bile ducts.
Cholecystectomy - surgery to remove the gallbladder.
Cholecystitis - inflammation of the gallbladder wall.
Cholecystography - X-ray that shows the flow of contrast fluid through the intestines into the gallbladder.
Cholecystokinin - hormone released in the small intestine; it stimulates the release of bile and pancreatic enzymes.
Choledocholithiasis - a condition characterized by gallstones in the bile ducts.
Cholelithiasis - a condition in which gallstones are present in the gallbladder.
Cholera - an acute, infectious disease caused by the consumption of water or food contaminated with the bacterium Vibrio cholerae.
Cholestasis - any interruption in the flow of bile.
Cholesteatoma - accumulation of dead cells in the middle ear caused by repeated middle ear infections.
Cholesterol - a waxy substance that is produced in the human body, animal fats, and in dairy products and is transported in the blood.
Chondroblasts - immature cartilage-producing cells.
Chorea - rapid, jerky, dance-like movement of the body.
Chorionic villus sampling (CVS) - diagnostic test, usually performed between the 10th and 12th weeks of pregnancy, in which a small sample of tissue is taken from the placenta and examined to detect genetic abnormalities in a fetus.
Choroid - the thin, blood-rich membrane that covers the whites of the eyeballs; responsible for supplying blood to the retina.
Chromatography - a laboratory test performed on a pregnant woman's urine to detect illegal drugs, such as cocaine, heroin, and marijuana.
Chromosomes - filaments of genetic material in every cell nucleus that are made up of genes and that transmit genetic information from one generation of cells to the next.
Chronic - referring to a disease or disorder that usually develops slowly and lasts for a long period of time.
Chronic fatigue syndrome (also called CFS or chronic fatigue and immune dysfunction syndrome) - a debilitating condition characterized by profound fatigue, not relieved by rest and not associated with another condition or disease.
Chronic lymphocytic leukemia (CLL) - a slowly progressing cancer of the blood in which too many lymphocytes, a type of white blood cell, are produced by the bone marrow and by organs of the lymph system.
Chronic myelogenous leukemia (CML) - a slowly progressing cancer of the blood in which too many white blood cells are produced in the bone marrow.
Chyme - thick liquid made of partially digested food and stomach juices; made in the stomach and moves into the small intestine for further digestion.
Ciliary body - the part of the eye that produces aqueous humor.
Cineangiography - the procedure of taking moving pictures to show the passage of dye through blood vessels.
Circulatory system - pertaining to the heart and blood vessels, and the circulation of blood.
Circumcision - surgical procedure to remove the skin covering the end of the penis, called the foreskin.
Cirrhosis - a long-term disease of the liver in which the liver becomes covered with fiber-like tissue and has difficulty removing toxins and poisonous substances from the body. Alcohol, medications, and other substances may build up in the bloodstream and cause problems. Cirrhosis may be a result of scarring and damage from other diseases, such as biliary atresia and alcoholism.
Claudication - pain or fatigue in arms and legs due to poor supply of oxygen to the muscles.
Cleft lip - an abnormality in which the lip does not completely form. The degree of the cleft lip can vary greatly, from mild (notching of the lip) to severe (large opening from the lip up through the nose).
Cleft palate - occurs when the roof of the mouth does not completely close, leaving an opening that can extend into the nasal cavity. The cleft may involve either side of the palate. It can extend from the front of the mouth (hard palate) to the throat (soft palate). The cleft may also include the lip.
Climacteric (also called perimenopause) - the transition period of time before menopause, marked by a decreased production of estrogen and progesterone, irregular menstrual periods, and transitory psychological changes.
Clinical trials - organized research studies that provide clinical data aimed at finding better ways to prevent, detect, diagnose, or treat diseases.
Clostridium difficile (C. difficile) - a strain of bacteria naturally present in the large intestine that make a substance that can cause a serious infection called pseudomembranous colitis in people taking antibiotics.
Coagulation disorders - problems with either the inability for blood to clot properly, resulting in excessive bleeding, or excessive clotting leading to obstruction of veins and arteries (thrombosis).
Coccydynia - pain around the coccyx.
Cochlea - snail-shaped structure in the inner ear that contains the organ of hearing.
Cochlear implant - medical device that bypasses damaged structures in the inner ear and directly stimulates auditory nerve to allow some deaf individuals to learn to hear and interpret sounds and speech.
Cognition - mental functions such as the ability to think, reason, and remember.
Cold knife cone biopsy - a procedure in which a laser or a surgical scalpel is used to remove a piece of tissue. This procedure requires the use of sedation or general anesthesia.
Cold sore - a small blister around and in the mouth caused by the herpes simplex virus.
Colectomy - partial or complete removal of the large bowel or colon.
Colic - attacks of abdominal pain, caused by muscle spasms in the intestines.
Colitis - irritation of the colon.
Collagen - a protein produced by skin cells that provide strength and resilience to the skin.
Collagen injections - a type of cosmetic procedure in which collagen, a protein, is injected to raise sunken scars or otherwise improve appearance. However, collagen is not safe in patients with certain diseases and retreatment is often necessary.
Collagen/fat injectable fillers (also called soft-tissue augmentation) - a plastic surgery technique used to correct wrinkles, depressions in the skin, and/or scarring.
Collagenous colitis - type of colitis caused by an abnormal thickening of a layer of the large intestine by collagen, a threadlike protein.
Colon - large intestine.
Colon polyps - small, fleshy, mushroom-shaped growths in the colon.
Colonic inertia - condition of the colon in which the muscles do not work properly, causing constipation.
Colonoscopic polypectomy - removal of tumor-like growths (polyps) using a device inserted through a colonoscope.
Colonoscopy - a test that uses a long, flexible tube with a light and camera lens at the end (colonoscope) to examine inside the large intestine.
Colorectal cancer - cancer that occurs in the colon (large intestine) or the rectum (the end of the large intestine).
Colorectal transit study - a test to show how well food moves through the colon. The patient swallows capsules containing small markers which are visible on x-ray. The patient follows a high-fiber diet during the course of the test, and the movement of the markers through the colon is monitored with abdominal x-rays taken several times three to seven days after the capsule is swallowed.
Colostomy - operation that makes it possible for stool to leave the body after the rectum has been removed.
Colostrum - thin, white, first milk produced by the breasts during late pregnancy and for a few days after childbirth. It provides a nursing infant with essential nutrients and infection-fighting antibodies.
Colposcopy (also called colposcopic biopsy) - a procedure which uses an instrument with magnifying lenses, called a colposcope, to examine the cervix for abnormalities. If abnormal tissue is found, a biopsy is usually performed.
Common bile duct - tube that carries bile from the liver to the small intestine.
Common bile duct obstruction - blockage of the common bile duct, often caused by gallstones.
Compact tissue - the harder, outer tissue of bones.
Comparative pathology - the study of disease in animals and how it compares in humans.
Complementary medicine - any form of therapy used in combination with other alternative treatments or standard/conventional medicine.
Complete blood count (CBC) - a measurement of size, number, and maturity of the different blood cells in a specific volume of blood.
Composite resins (also called white fillings) - a tooth-colored plastic mixture filled with glass (silicon dioxide) that is used primarily for cosmetic improvements of the smile by changing the color of the teeth or reshaping disfigured teeth.
Compound fracture - a broken bone that protrudes through the skin.
Computed tomography scan (also called a CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.
Conductive hearing impairment - hearing loss caused by dysfunction of the outer or middle ear.
Cone biopsy (also called conization) - a biopsy in which a larger, cone-shaped piece of tissue is removed from the cervix by using the loop electrosurgical excision procedure or the cold knife cone biopsy procedure. The cone biopsy procedure may be used as a treatment for precancerous lesions and early cancers.
Congenital - present at birth.
Congenital anomaly - a health problem present at birth (not necessarily genetic).
Congestive heart failure - a condition in which the heart cannot pump out all of the blood that enters it, which leads to an accumulation of blood in the vessels and fluid in the body tissues.
Conjunctiva - the membrane that lines the exposed eyeball and the inside of the eyelid.
Conjunctivitis - inflammation of the conjunctiva of the eye.
Constipation - a condition in which stool becomes hard and dry.
Constrict - tighten; narrow.
Contact dermatitis - a rash or an inflammation of the skin caused by an exposure to an allergen or an irritant.
Continence - ability to hold in a bowel movement or urine.
Continent ileostomy - operation to create a pouch from part of the small intestine. Stool that collects in the pouch is removed by inserting a small tube through an opening made in the abdomen.
Contractions, labor - rhythmic tightening of the muscular wall of the uterus to push the fetus down through the vagina during childbirth.
Contracture - inability to move a joint due to a permanent rigidity or contraction of a muscle.
Contusion (Also called bruise.) - a collection of blood due to broken blood vessels underneath the skin usually caused by trauma. A bruise causes discoloration and swelling in the area.
Corn - a yellowish, callus growth that develops on top of the toes.
Cornea - the clear, dome-shaped surface that covers the front of the eye.
Corneal curvature - the shape of the front surface of the eye.
Coronal suture - the joining line (suture) between the frontal and parietal bones of the skull that crosses the top of the skull from temple to temple.
Coronary arteries - arteries that come from the aorta to provide blood to the heart muscle.
Coronary artery bypass graft (CAB or CABG) - a surgical procedure in which a healthy blood vessel is transplanted from another part of the body into the heart to replace or bypass a diseased vessel.
Coronary artery spasm - a sudden closing of an artery, which cuts off blood flow to the heart and causes symptom of angina or heart attack.
Coronary heart disease - a condition in which the coronary arteries narrow from an accumulation of plaque (atherosclerosis) and cause a decrease in blood flow.
Coronary occlusion - an obstruction of one of the coronary arteries that decreases flow to the heart muscle.
Coronary thrombosis - the formation of a clot in one of the arteries that carry blood to the heart muscle.
Cortex - the outer layer of the cerebrum, densely packed with nerve cells.
Corticosteroids (also called glucocorticoids) - potent, anti-inflammatory hormones that are made naturally in the body or synthetically for use as drugs; most commonly prescribed drug of this type is prednisone.
Cosmetic plastic surgery (also called aesthetic plastic surgery) - one type of plastic surgery performed to repair or reshape otherwise normal structures of the body, primarily to improve the patient's appearance and self-esteem.
Craniectomy - excision of a part of the skull.
Craniofacial - pertaining to the head (skull) and face.
Craniosynostosis - a condition in which the sutures (soft spots) in the skull of an infant close too early, causing problems with normal brain and skull growth. Premature closure of the sutures may also cause the pressure inside of the head to increase and the skull or facial bones to change from a normal, symmetrical appearance to an abnormal, asymmetrical appearance.
Craniotomy - surgical opening of the skull to gain access to the intracranial structures.
Creeping eruption - a skin infection, caused by hookworms, that is characterized by severe itching.
Crepitus - grinding noise or sensation within a joint.
Crohn's disease (also called regional enteritis and ileitis) - a chronic form of inflammatory bowel disease that usually affects the lower small intestine (called the ileum) or the colon, but can also affect the entire gastrointestinal tract.
Crouzon syndrome - a genetic birth defect characterized by abnormalities in the skull and facial bones. This syndrome often causes the skull to be short in the front and the back. Flat cheek bones and a flat nose are also typical of this disorder.
Crown - a "cap" that covers a cracked or broken tooth, unfixed by a filling, to approximate its normal size and shape.
Crust (also called scab) - a formation of dried blood, pus, or other skin fluid over a break in the skin.
Cryosurgery - use of liquid nitrogen, or a probe that is very cold, to freeze and kill cancer cells.
Cryoprostatectomy - freezing of the prostate through the use of liquid nitrogen probes guided by transrectal ultrasound of the prostate.
Cryothalamotomy - a surgical procedure in which a super-cooled probe is inserted into a part of the brain called the thalamus in order to stop tremors.
Cryptorchidism - failure of one or both of the testicle(s) to move down into the scrotum.
Cryptosporidium - a parasite that can cause gastrointestinal infection and diarrhea.
Cryptosporidiosis - a diarrheal infection caused by the parasite Cryptosporidium. The parasite is transmitted after drinking or swallowing contaminated food or water, including water swallowed while swimming.
Cubital tunnel - a tunnel of muscle, ligament, and bone on the inside of the elbow.
Cued speech - method of communication that combines speech reading with a system of handshapes placed near the mouth to help deaf or hard-of-hearing individuals differentiate words that look similar on the lips.
Culdocentesis - a procedure in which a needle is inserted into the pelvic cavity through the vaginal wall to obtain a sample of pus.
Cupping - the use of warmed glass jars to create suction on certain points of the body.
Cyanosis - bluish discoloration of the skin from lack of oxygen.
Cyclic vomiting syndrome (CVS) - sudden, repeated attacks of severe vomiting (especially in children), nausea, and physical exhaustion with no apparent cause.
Cyst - a fluid-filled or semi-solid sac in or under the skin.
Cystic duct - tube that carries bile from the gallbladder into the common bile duct and the small intestine.
Cystic duct obstruction - blockage of the cystic duct, often caused by gallstones.
Cystitis - inflammation of the bladder, usually caused by a bacterial infection.
Cystocele - condition in which weakened pelvic muscles cause the base of the bladder to drop from its usual position down into the vagina.
Cystometry - diagnostic procedure that measures bladder capacity and pressure changes as the bladder fills and empties.
Cystoscopy (also called cystourethroscopy) - a procedure in which a cystoscope, a flexible tube and viewing device, is inserted through the urethra to examine the bladder and urinary tract for structural abnormalities or obstructions, such as tumors or stones.
Cystourethrocele - condition that results when the urethra and its supporting tissues weaken and drop into the vagina leading to stress incontinence.
Cystourethrogram (also called a voiding cystogram) - a specific X-ray that examines the urinary tract. A catheter (hollow tube) is placed in the urethra (tube that drains urine from the bladder to the outside of the body) and the bladder is filled with a liquid dye. X-ray images will be taken as the bladder fills and empties.
Cytology - the study of individual cells.
Cytomegalovirus - one group of herpes viruses that infects humans and can cause a variety of clinical symptoms including deafness or hearing impairment; infection with the virus may be either before or after birth.