Medical terms A–Z

Wide, blind-ended and full of liquid contents, it hides trouble for longer than the narrow left side of the colon does.

A fragrant oil sold for aromatherapy and for repelling insects, distilled from several unrelated trees, most of which are not cedars.

Cefepime is a broad spectrum antibiotic from a later cephalosporin generation, given intravenously to treat serious infections including certain resistant bacteria.

Broad coverage is not complete coverage, and what ceftriaxone misses, including Pseudomonas and enterococci, matters as much as what it reaches.

A digestive disease that is caused by an immune response to a protein called gluten, which is found in wheat, rye, barley, and oats.

Everything a body does happens inside one of these compartments, which is why disease is ultimately described at this scale.

The laboratory craft of keeping living cells growing outside the body, which depends more on excluding contamination than on feeding them.

Most cells in the body are not in the cycle at all, so the interesting question is what pulls them back into it.

How one fertilized egg becomes hundreds of cell types without changing its genes, and the yardstick a pathologist uses to grade a tumor.

The ability of a cell to move.

An increase in the number of cells as a result of cell growth and cell division.

The controlled release of energy from food inside a cell, captured as ATP rather than lost all at once as heat.

Cells cannot see each other, so everything they coordinate has to travel as a molecule, a touch, or a direct electrical link.

The close adherence (bonding) to adjoining cell surfaces.

A treatment used to help the immune system fight diseases, such as cancer and infections with certain viruses.

Two opposite streams of chemistry running at once inside every cell, one tearing molecules down and one building them up.

Redness appearing on both legs at once is rarely cellulitis, since the infection almost always settles on one side only.

Cellulose is the fibrous carbohydrate forming plant cell walls that passes through the human digestive tract largely undigested.

Cancer that has spread from the original (primary) tumor to the central nervous system (CNS).

Chemotherapy or radiation therapy given to the central nervous system (CNS) as a preventive treatment.

A tumor of the central nervous system, including brain stem glioma, craniopharyngioma, medulloblastoma, and meningioma.

A tube surgically placed into a blood vessel for the purpose of giving intravenous fluid and drugs.

A substance being studied in the treatment of some types of cancer.

A drug being studied in the treatment of acute leukemias and some other types of cancer.

Cephalosporins are a large class of antibiotics related to penicillins, grouped into generations with differing ranges of bacterial coverage.

A benign, slow-growing tumor in the cerebellum (part of the brain at the back of the head), made up of abnormal blood vessel growth.

Having to do with two structures of the brain, the cerebellum (located at the lower back of the brain) and the pons (located at the base of the brain in front of the cerebellum) and the area between…

Damage on one side shows on the same side of the body, the opposite of what the rest of the brain does.

One half of the cerebrum, the part of the brain that controls muscle functions and also controls speech, thought, emotions, reading, writing, and learning.

Cerebrospinal fluid cushions the brain and spinal cord, circulating through the fluid filled spaces that surround these structures and helping clear cellular waste.

A process used to drain fluid that has built up around the brain and spinal cord.

Each half controls the opposite side of the body, so the site of an injury predicts which side loses function.

Ceremony describes a formal event marking a significant occasion or transition, a concept relevant to end of life, cultural, and professional health care practices.

Years usually pass between the first abnormal cells and an invasive tumor, and that long window is what screening exploits.

Cervical intraepithelial neoplasia describes abnormal cell growth confined to the surface layer of the cervix, identified through routine screening.

Surgery to remove the cervix (the end of the uterus that forms a canal between the uterus and the vagina).The upper part of the vagina and certain pelvic lymph nodes may also be removed.

A device used to deliver drugs directly to the cervix (the lower, narrow end of the uterus that forms a canal between the uterus and vagina).

Being reachable from outside the body is what makes this organ unusual, because its surface cells can be sampled and examined directly.

A substance that increases production of saliva and tears.

A substance that is being studied in the treatment of cancer.

A substance being studied in the treatment of cancer.

A procedure in which a tube is inserted into the chest to view the tissues and organs in the area between the lungs and between the breastbone and heart.

A type of external radiation therapy that uses a special machine to make invisible, high-energy particles (protons or helium ions) that kill cancer cells.

A molecule with several arms that close around a metal ion, holding it so tightly the body passes it out unchanged.

A procedure used to improve the way certain skin problems look.

A procedure used to improve the way certain skin problems look.

Water, oxygen and every medicine ever made are chemicals, so the word describes composition rather than whether something is natural or harmful.

A phrase used in two quite different ways: a measurable disturbance in body chemistry, and a loose shorthand for mental illness.

A chemical peel applies a solution to the skin to remove its outer layers, improving the appearance of scars, wrinkles, or sun damage.

A procedure in which the blood supply to the tumor is blocked surgically or mechanically and anticancer drugs are administered directly into the tumor.

Chemotherapy combined with immunotherapy.

The use of drugs, vitamins, or other agents to try to reduce the risk of, or delay the development or recurrence of, cancer.

In cancer prevention, a clinical trial that studies whether taking certain medicines, vitamins, minerals, or food supplements can prevent cancer.

A quality of some drugs used in cancer treatment.

Two treatments given in the same weeks so that one sensitizes the tumor to the other, at the cost of harsher side effects.

Treatment that combines chemotherapy with radiation therapy.

The susceptibility of tumor cells to the cell-killing effects of anticancer drugs.

A laboratory test that measures the number of tumor cells that are killed by a cancer drug.

A drug that makes tumor cells more sensitive to the effects of chemotherapy.

A drug used to treat cancer.

Given in cycles rather than continuously, so the healthy tissues that renew fastest have time to recover between rounds.

The muscles, bones, and joints that make up the area of the body between the neck and the abdomen.

A chest x-ray uses a brief pulse of radiation to produce an image of the lungs, heart, and bones of the chest for evaluation.

An anatomy term for an X-shaped crossing (for example, of nerves or tendons).

A professional who is responsible for making a child's hospital and treatment experience less scary.

Chimeric describes an organism, tissue, or molecule composed of genetically distinct cell populations or parts originating from more than one source.

In traditional Chinese medicine, meridians are channels that form a network in the body, through which qi (vital energy) flows.

The root of this plant has been used in some cultures to treat certain medical problems.

A drug used to help diagnose gastrinomas (tumors that cause too much gastric acid to be made) and other problems with the pancreas.

The tough material that forms insect shells and fungal cell walls, and a useful drug target precisely because humans do not make it.

Chlorine is a chemical element widely used to disinfect water and surfaces by killing bacteria and other microorganisms.

A solid lump made of leukemia cells growing outside the marrow, which can appear before anything abnormal shows up in the blood.

A substance being studied in the diagnosis and treatment of glioma (a type of brain cancer) and other types of cancer.

Location drives almost everything here, since a tumor deep inside the liver behaves and is assessed quite differently from one near the intestine.

The name is precise, but it is not always used precisely, and some writing applies it loosely to any cancer of the bile ducts.

Most of these stones sit silently in the gallbladder for life; the trouble begins only when one moves and blocks a duct.

Yellow skin, itching, dark urine and pale stools all trace back to bile that cannot leave the liver by its usual route.

There is no good or bad cholesterol, only good and bad carriers: the molecule is identical, and the particle transporting it differs.

Choline is an essential nutrient the body uses to build cell membranes and the neurotransmitter acetylcholine, and to move fat out of the liver.

Chondrocytes are the sole resident cells of cartilage, embedded within the tissue's own matrix and responsible for producing and maintaining it.

A long sugar chain bristling with negative charge, which drags in water and lets cartilage spring back after every step.

Chondrosarcoma is a cancer that forms in cartilage, most often affecting the pelvis, ribs, or the ends of long bones.

CHOP is a four drug chemotherapy combination built from cyclophosphamide, doxorubicin, vincristine, and prednisone, most often used to treat non-Hodgkin lymphoma.

An abbreviation for a chemotherapy combination that is used to treat non-Hodgkin lymphoma.

A rare midline bone tumor grown from embryonic leftovers, slow to develop but stubbornly local and prone to returning.

A type of cancer that grows into the muscular wall of the uterus.

The membrane in hens' eggs that helps chicken embryos get enough oxygen and calcium for development.

A malignant, fast-growing tumor that develops from trophoblastic cells (cells that help an embryo attach to the uterus and help form the placenta).

A fast-growing tumor of placental cells that reaches the lungs early yet responds remarkably well to chemotherapy.

A malignant, fast-growing tumor that develops from trophoblastic cells (cells that help an embryo attach to the uterus and help form the placenta).

A malignant, fast-growing tumor that develops from trophoblastic cells (cells that help an embryo attach to the uterus and help form the placenta).

A thin layer of tissue that is part of the middle layer of the wall of the eye, between the sclera (white outer layer of the eye) and the retina (the inner layer of nerve tissue at the back of the…

A rare type of cancer that occurs in the ventricles of the brain.

A type of cell that makes neurohormones (chemicals that are made by nerve cells and used to send signals to other cells) and releases them into the blood.

Chromatography is a laboratory technique that separates the components of a mixture as they travel at different rates through an absorbing material.

Packaging is the point, since the DNA in one cell would stretch about two meters and chromosomes fold it to fit inside a nucleus.

The word says nothing about how serious a problem is, only that it has lasted, and a chronic illness may be entirely stable.

Inflammation of the prostate gland that is caused by a bacterial infection and that continues or gets worse over a long period of time.

A disease in which too many eosinophils (a type of white blood cell) are found in the bone marrow, blood, and other tissues.

A condition lasting for more than 6 months in which a person feels tired most of the time and may have trouble concentrating and carrying out daily activities.