top of page

Glossaries - C

We've defined thousands of terms related to health care. This page discusses glossary terms with the letter C.


A substance that the pancreas releases into the bloodstream in equal amounts to insulin. A test of C-peptide levels will show how much insulin the body is making.


A hormone secreted by the thyroid that lowers blood calcium. Often used in the treatment of hypercalcemia.


A mineral found in the teeth, bones, and other body tissues.

Calcium Channel Blocker

A drug used to lower blood pressure.

Calculi (KAL-kyoo-ly)

Stones or solid lumps such as gallstones.


A small area of skin, usually on the foot, that has become thick and hard from rubbing or pressure. Calluses may lead to other problems such as serious infection. Shoes that fit well can keep calluses from forming.


The energy unit for measuring heat. Energy that comes from food. Some foods have more calories than others. Fats have many calories. Most vegetables have few. People with diabetes are advised to follow meal plans with suggested amounts of calories for each meal and/or snack. See also: Meal plan; exchange lists.

Campylobacter pylori (KAM-pee-loh-BAK-tur py-LOH-ree)

The original name for the bacterium that causes ulcers. The new name is Helicobacter pylori. See also Helicobacter pylori.

Candida Albicans

A normally harmless microscopic yeast that lives within the human gastrointestinal tract, it can overgrow and cause fatigue, depression, joint pain, headaches, and recurrent infections.

Candidiasis (KAN-di-DY-uh-sis)

An infection caused by the Candida (KAN-di-duh) fungus, which lives naturally in the gastrointestinal tract. Infection occurs when a change in the body, such as surgery, causes the fungus to overgrow suddenly.


The smallest of the body's blood vessels. Capillaries have walls so thin that oxygen and glucose can pass through them and enter the cells, and waste products such as carbon dioxide can pass back into the blood to be carried away and taken out of the body. Sometimes people who have had diabetes for a long time find that their capillaries become weak, especially those in the kidney and the retina of the eye. See also: Blood vessels.


One of the three main classes of foods and a source of energy. Carbohydrates are mainly sugars and starches that the body breaks down into glucose (a simple sugar that the body can use to feed its cells). The body also uses carbohydrates to make a substance called glycogen that is stored in the liver and muscles for future use. If the body does not have enough insulin or cannot use the insulin it has, then the body will not be able to use carbohydrates for energy the way it should. This condition is called diabetes. See also: Fats; protein.

Carcinogen (kar-SIN-o-jin)

A substance or agent that is known to cause cancer.


A doctor who sees and takes care of people with heart disease; a heart specialist.


Relating to the heart and blood vessels (arteries, veins, and capillaries); the circulatory system.

Clear Image

Caroli's Disease (kuh-ROH-leez duh-zeez)

Caroli's Disease (kuh-ROH-leez duh-zeez)

Clear Image

Carpal Tunnel Syndrome

A nerve disorder affecting the hand that may occur in people with diabetes; caused by a pinched nerve.

Normal Joint


A tough, stretchy tissue that covers the ends of bones to form a low-friction, shock-absorbing surface for joints.


Clouding of the lens of the eye. In people with diabetes, this condition is sometimes referred to as "sugar cataract.".


Breaking down of proteins and other chemical compounds in the body. Catabolism results in a weakening of bone and muscle tissue, a loss in skin resilience, as well as a general decline in other important body functions.

Catalyze (KAT-ah-lies)

to greatly accelerate a chemical reaction; enzymes, for example, are protein catalysts that speed up biochemical reactions in the body; the enzyme is not consumed in the process.

Catheter (KATH-uh-tur)

A thin, flexible tube that carries fluids into or out of the body. When a catheter is place in a vein, it provides a pathway for drugs, nutrients, or blood products. Blood samples also can be removed through the catheter.

CD4+ T lymphocyte

immune cell that carries a marker on its surface known as "cluster of differentiation 4" (CD4). These cells are the primary targets of HIV. Also known as helper T cells, CD4+ T cells help orchestrate the immune response, including antibody responses as well as killer T cell responses. (See also T cell).

CD8+ T lymphocyte

immune cell that carries the "cluster of differentiation 8" (CD8) marker. CD8 T cells may be cytotoxic T lymphocytes or suppressor T cells. (See also cytotoxic T lymphocyte (CTL); T cell).

Cecostomy (see-KAW-stuh-mee)

A tube that goes through the skin into the beginning of the large intestine to remove gas or feces. This is a short-term way to protect part of the colon while it heals after surgery.

Cecum (SEEK-um)

The beginning of the large intestine. The cecum is connected to the lower part of the small intestine, called the ileum.

Celiac Disease (SEL-ee-ak duh-zeez)

Inability to digest and absorb gliadin, the protein found in wheat. Undigested gliadin causes damage to the lining of the small intestine. This prevents absorption of nutrients from other foods. Celiac disease is also called celiac sprue, gluten intolerance, and nontropical sprue.


The primary unit of physical life, whose integral structure and optimal status is crucial for the healthy functioning of the human body.

Cell membrane

The surrounding border of the cell, formed of proteins and lipids, that encloses the cell and controls the movement of substances inside and outside of the cell.

Cell-mediated immunity (cellular immunity)

the immune response coordinated by helper T cells and CTLs. This branch of the immune system targets cells infected with microorganisms such as viruses, fungi and certain bacteria.

Cerebrovascular disease

Damage to the blood vessels in the brain, resulting in a stroke. The blood vessels become blocked because of fat deposits or they become thick and hard, blocking the flow of blood to the brain. Sometimes, the blood vessels may burst, resulting in a hemorrhagic stroke. People with diabetes are at higher risk of cerebrovascular disease. See also: Macrovascular disease; stroke.

Charcot Foot

A foot complication associated with diabetic neuropathy that results in destruction of joints and soft tissue. Also called "Charcot's joint" and "neuropathic arthropathy".

Chemoreceptor (KEE-mow-ree-SEP- tor)

a molecular structure on the surface of a cell that is sensitive to chemical substances, such as epinephrine released by nerve cell.

Chemotaxis (kem-oh-TACK-sis)

movement or response of cells to chemical.


Treatment with anticancer drugs. Chemotherapy may be taken by mouth or it may be put into the body by a needle inserted into a vein or muscle.

Chlorhydria (klor-HY-dree-uh)

Too much hydrochloric acid in the stomach.

Cholangiography (koh-LAN-jee-AW-gruh-fee)

A series of x-rays of the bile ducts.

Cholangitis (KOH-lan-JY-tis)

Irritated or infected bile ducts.

Cholecystectomy (KOH-lee-sis-TEK-tuh-mee)

An operation to remove the gallbladder.

Cholecystitis (KOH-lee-sis-TY-tis)

An irritated gallbladder.

Cholecystogram, Oral (KOH-lee-SIS-tuh-gram, OH-rul)

An x-ray of the gallbladder and bile ducts. The patient takes pills containing a special dye to make the organs show up in the x-ray. Also called oral cholecystography.

Cholecystokinin (KOH-lee-sis-tuh-KY-nin)

A hormone released in the small intestine. Causes muscles in the gallbladder and the colon to tighten and relax.

Choledocholithiasis (KOH-lee-doh-koh-luh-THY-uh-sis)

Gallstones in the bile ducts.

Cholelithiasis (KOH-lee-luh-THY-uh-sis)

Gallstones in the gallbladder.

Cholestasis (KOH-lee-STAY-sis)

Blocked bile ducts. Often caused by gallstones.

Cholesterol (koh-LES-tuh-rawl)

A fat-like substance found in blood, muscle, liver, brain, and other tissues in people and animals. The body makes and needs some cholesterol. Too much cholesterol, however, may cause fat to build up in the artery walls and cause a disease that slows or stops the flow of blood. Butter and egg yolks are foods that have a lot of cholesterol.

Cholinergic Parasympathomimetic Agent (ko-lin-ER-jik pah-rah-sim-pah-tho-mee-MET-ik)

a chemical substance that causes the release of choline (acetylcholine) from parasympathetic nerve ending.


referring to the chorion or membrane enclosing the fetus.

Chronic (KRAW-nik)

Present over a long period of time. Diabetes is an example of chronic disease.

Chyme (kym)

Food that has been stored, dissolved, and partially digested by the stomach into a solution of hydrochloric acid, enzymes, and food particle.


The flow of blood through the heart and blood vessels of the body.

Cirrhosis (suh-ROH-sis)

A chronic liver condition caused by scar tissue and cell damage. Cirrhosis makes it hard for the liver to remove poisons (toxins) like alcohol and drugs from the blood. These toxins build up in the blood and may affect brain function.

Clinical trial

A scientifically controlled study carried out in people, usually to test the effectiveness of a new treatment.

Clostridium difficile (C. difficile) (klaws-TRID-ee-um deef-ee-seel)

Bacteria naturally present in the large intestine. These bacteria make a substance that can cause a serious infection called pseudomembranous colitis in people taking antibiotics.

Cluster headaches

Intensely painful headaches-occurring suddenly and lasting between 30 and 45 minutes-named for their repeated occurrence in groups or clusters. They begin as minor pain around one eye and eventually spread to that side of the face.


groups of individuals who share one or more characteristics in a research study and who are followed over time. For example, a HIV vaccine trial might include two cohorts, a group at low risk for HIV and a group at higher risk for HIV.

Colectomy (koh-LEK-tuh-mee)

An operation to remove all or part of the colon.

Colic (KAWL-ik)

Attacks of abdominal pain, caused by muscle spasms in the intestines. Colic is common in infants.

Colitis (koh-LY-tis)

Irritation of the colon.


The major protein that is one of the main building blocks of skin, tendon, bone, cartilage, and other connective tissues.

Collagenous Colitis (koh-LAH-juh-nus koh-LY-tis)

A type of colitis. Caused by an abnormal band of collagen, a thread-like protein.

Colon (KOH-lun)

Colonic Inertia (koh-LAWN-ik ih-NUR-sha)

A condition of the colon. Colon muscles do not work properly, causing constipation.

Colonoscopy (koh-luh-NAW-skuh-pee)

A test to look into the rectum and colon. The doctor uses a long, flexible, narrow tube with a light and tiny lens on the end. This tube is called a colonoscope.

Colonoscopic Polypectomy (KOH-luh-nuh-SKAW-pik pawl-up-EK-tuh-mee)

The removal of tumor-like growths (polyps) using a device inserted through a colonoscope.

Colony-stimulating factors

Substances that stimulate the production of blood cells. Treatment with colony-stimulating factors (CSF) can help the blood- forming tissue recover from the effects of chemotherapy and radiation therapy. These include granulocyte colony-stimulating factors (G-CSF) and granulocyte-macrophage colony-stimulating factors (GM-CSF).

Colon polyps (KOH-lun PAWL-ups)

Small, fleshy, mushroom-shaped growths in the colon.

Coloproctectomy (koh-loh-prahk-TEK-tuh-mee)

Colorectal Cancer (koh-loh-REK-tul-CAN-sir)

Cancer that occurs in the colon (large intestine) or the rectum (the end of the large intestine). A number of digestive diseases may increase a person's risk of colorectal cancer, including polyposis and Zollinger-Ellison Syndrome.

Colorectal Transit Study (koh-loh-REK-tul TRAN-zit STUH-dee)

A test to see how food moves through the colon. The patient swallows capsules that contain small markers. An x-ray tracks the movement of the capsules through the colon.

Colostomy (koh-LAW-stuh-mee)

An operation that makes it possible for stool to leave the body after the rectum has been removed. The surgeon makes an opening in the abdomen and attaches the colon to it. A temporary colostomy may be done to let the rectum heal from injury or other surgery.

Common Bile Duct Obstruction (KAH-mun BY-ul dukt ub-STRUK-shun)

A blockage of the common bile duct, often caused by gallstones.

Complement (KOM-pleh-ment)

blood proteins that play an important role in the immune response. Generally, complement proteins amplify the effects of antibodies and inflammation. ALSO, a functionally related system comprising at least 20 distinct serum proteins; the proteins help in the destruction of foreign cells identified by the immune system and have other biologic functions.

Computed Tomography (CT) Scan (kom-PYOO-ted tuh-MAW-gruh-fee)

An x-ray that produces three-dimensional pictures of the body. Also known as computed axial tomography (CAT) scan.

Congenital defects

Problems or conditions that are present at birth.

Congestive heart failure

Heart failure caused by loss of pumping power by the heart, resulting in fluids collecting in the body. Congestive heart failure often develops gradually over several years, although it also can happen suddenly. It can be treated by drugs and in some cases, by surgery.

Connective tissue

The supporting framework of the body and the internal organs - including bone, cartilage, and ligaments.

Constipation (kon-stuh-PAY-shun)

A condition in which the stool becomes hard and dry. A person who is constipated usually has fewer than three bowel movements in a week. Bowel movements may be painful. For detailed information go here.

Continence (KON-tuh-nuns)

The ability to hold in a bowel movement or urine.

Continent Ileostomy (KON-tuh-nunt il-ee-AW-stuh-mee)

An 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. See also Ileostomy.

Continuous Infusion

The slow introduction of a fluid into a vein or artery over a period of time.


A condition that makes a treatment not helpful or even harmful.


in clinical trials, the control group is given either the standard treatment for the disease or an inactive substance called a placebo. The control group is compared with one or more groups of volunteers given experimental treatments to detect any effects of the treatments.

Coronary disease

Damage to the heart. Not enough blood flows through the vessels because they are blocked with fat or have become thick and hard; this harms the muscles of the heart. People with diabetes are at a higher risk of coronary disease. For detailed information go here.

Corticosteroids (KOR-tuh-koh-STEER-oydz)

Medicines such as cortisone and hydrocortisone. These medicines reduce irritation from Crohn's disease and ulcerative colitis. They may be taken either by mouth or as suppositories. These medications are not favorable to the body because the suppress the immune system. When taken over a long period of time, I have observed some of the sickest people that have visited my office.


A hormone produced by the adrenal glands in response to stress, affecting the body's metabolism of glucose, proteins, and fats. Cortisol is normally released by the body in a regular daily pattern of highs and lows. Imbalances are associated with fatigue, depression, obesity, and immune dysfunction.

Coumarin (KOO-muh-rin)

a compound derived from sweet clover and other plants, and also prepared synthetically, which contains a factor, dicumarol, which inhibits the hepatic synthesis of the vitamin K-dependent coagulation factors (prothrombin, factors VII, IX, and X). Dicumarol derivatives are used as anticoagulants in the treatment of disorders in which there is excessive or undesirable clotting.


A chemical found in the blood and passed in the urine. A test of the amount of creatinine in blood or in blood and urine shows if the kidney is working right or if it is diseased. This is called the creatinine clearance test.

Crohn's Disease (krohnz duh-zeez)

A chronic form of inflammatory bowel disease. Crohn's disease causes severe irritation in the gastrointestinal tract. It usually affects the lower small intestine (called the ileum) or the colon, but it can affect the entire gastrointestinal tract. Also called regional enteritis and ileitis. For a complete discussion of Crohn's Disease go here. See also Inflammatory Bowel Disease (IBD) and Granuloma.

Cryptosporidia (KRIP-toh-spoh-RID-ee-uh)

A parasite that can cause gastrointestinal infection and diarrhea. See also Gastroenteritis.


Cyclic Vomiting Syndrome (CVS) (SIK-lik VOM-uh-ting sin-drohm)

Sudden, repeated attacks of severe vomiting (especially in children), nausea, and physical exhaustion with no apparent cause. Can last from a few hours to 10 days. The episodes begin and end suddenly. Loss of fluids in the body and changes in chemicals in the body can require immediate medical attention. Also called abdominal migraine.

Cystic Duct (SIS-tik dukt)

The tube that carries bile from the gallbladder into the common bile duct and the small intestine.

Cystic Duct Obstruction (SIS-tik dukt ub-STRUK-shun)

A blockage of the cystic duct, often caused by gallstones.


a soluble, hormone-like protein produced by white blood cells that acts as a messenger between cells. Cytokines can stimulate or inhibit the growth and activity of various immune cells. Cytokines are essential for a coordinated immune response and can also be used as immunologic adjuvants. HIV replication, for example, is regulated by a delicate balance among cytokines.


the living matter within a cell (excluding the nucleus) that is responsible for the function of the cell (for example, protein synthesis).

Cytotoxic (sigh-toe-TOCK-sick)

destructive to a cell.

Cytotoxic T Cells, Cytotoxic T lymphocyte (CTL)

White blood cells that can directly destroy specific cells. T cells can be separated from other blood cells and grown in the laboratory and then be given to the patient to destroy tumor cells. Certain drugs can also assist in the formation of cytotoxic T cells within the patient's body.

Immune system cell that can destroy cancer cells and cells infected with viruses, fungi or certain bacteria. CTLs, also known as killer T cells, carry the CD8 marker. CTLs kill virus-infected cells, whereas antibodies generally target free-floating viruses in the blood. CTL responses are a proposed but unproven correlate of HIV immunity. (See also CD8+ T lymphocyte).

bottom of page