Medical terms A–Z

Parts of the flowering plant have been used in some cultures to treat certain medical problems.

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

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

A trade name for turmeric, a spice that is not saffron, is not related to saffron, and costs a small fraction of what saffron costs.

A plant whose roots are used as a sedative and to treat certain medical conditions.

Regulators approve drugs for named indications, yet prescribing outside that list is legal, common, and described as off-label use.

A drug that interferes with the ability of a virus to make copies of itself.

An exam of the inside of the back of the eye using a beam of light and a hand-held lens.

An anticancer drug belonging to a family of drugs called radiopharmaceuticals.

A word meaning painless that drifted into meaning slow, and a label promising more comfort than it can deliver.

A type of lymphoma that tends to grow and spread slowly, and has few symptoms.

Initial treatment used to reduce a cancer.

An inherited disorder in which there is a lower-than-normal number of neutrophils (a type of white blood cell that is important in fighting infections).

Invasion and multiplication of a microorganism in or on the body.

The inferior vena cava is the body's largest vein, returning oxygen poor blood from the lower body and abdomen to the heart.

The word describes a couple as often as a person, since the cause lies with either partner or with both about equally often.

Infertility is the inability to conceive after a defined period of trying, arising from causes affecting either partner or both together.

Cancer that has spread from where it started in the breast into surrounding, healthy tissue.

Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues.

The most common type of invasive breast cancer.

Useful in the short term and damaging when it persists, inflammation is protective or destructive depending largely on how long it lasts.

Calling a condition inflammatory says how the damage is being done, not what set it off, and those two questions stay separate.

A general term that refers to the inflammation of the colon and rectum.

A type of breast cancer in which the breast looks red and swollen and feels warm.

One of three types of virus that cause the illness called influenza (flu).

Informed consent is the process of giving a person the facts needed to decide, voluntarily, whether to undergo a treatment, procedure, or research study.

A technique in which abnormal tissue is exposed to a burst of infrared light (a type of radiation).

In medicine, a procedure in which an infrared camera (one that senses heat) is used to measure temperature differences on the surface of the body.

Rate is the whole point, since spreading a dose across time changes how a substance is tolerated, not merely how long it takes.

Swallowing food, a medication, or a harmful substance by mouth is called ingestion, a term used both in nutrition and in poisoning evaluations.

An operation in which the testicle is removed through an incision in the groin.

Inhalation is the physical act of drawing air or another substance into the lungs, the route used for gases, aerosols, and certain inhaled medications.

An inhaler delivers medication as a fine mist or powder breathed into the lungs through the mouth, most often for asthma or COPD.

Every inherited change is genetic, but plenty of genetic changes are not inherited, and the difference decides who else is at risk.

Describes a condition that cannot be treated by surgery.

A substance found in many foods that come from plants, including corn, wheat, rice, and soybeans, and in large amounts in cereals and legumes.

A substance being studied in the diagnosis of lung diseases, including lung cancer.

Daytime consequences rather than hours counted are what define it, since a short sleeper without them does not have insomnia.

In medicine, a method used to put a liquid into the body slowly or drop by drop.

Only the beta cells of the pancreatic islets make insulin, while their alpha cell neighbors make glucagon, the hormone that does the opposite.

A drug used to control the amount of sugar in the blood of patients with diabetes.

A drug used to control the amount of sugar in the blood of patients with diabetes.

A drug used to control the amount of sugar in the blood of patients with diabetes mellitus.

Named for its resemblance to insulin, this protein is the reason growth hormone lengthens bone without acting on it directly.

A protein found on the surface of some types of cells that binds to insulin-like growth factor (IGF).

A small pancreatic tumor that keeps releasing insulin when blood sugar is already low, producing confusing spells of odd behavior.

Treatment that is given after cancer has disappeared following the initial therapy.

In biochemistry, a type of molecule that binds to DNA and inserts itself into the DNA structure.

Named for interfering with viruses, these proteins warn neighboring cells before infection reaches them and cause the flu-like feeling of being ill.

A drug used to treat some infections caused by viruses and several types of cancer.

The short-range chemical messages that immune cells send one another in order to coordinate a response.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.

A type of lymphoma that grows and spreads quickly and has severe symptoms.

A physical examination in which the health care professional will feel for lumps or changes in the shape of the vagina, cervix, uterus, fallopian tubes, ovaries, and rectum.

A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor.

A measure of what a substance does rather than how much it weighs, agreed internationally so different products can be compared.

A doctor who specializes in internal medicine.

A hormone made in the pituitary gland.

A type of internal radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into a tumor or body tissue.

So broad that it means little on its own, the word almost always travels with a description of what was actually done.

The group receiving the study agent that is being tested in a clinical trial or clinical study.

As a modifier the word says little on its own; what matters is which segment of intestine a finding actually involves.

Resident microbes in their trillions, doing chemical work the human body never evolved the enzymes to do for itself.

Bacteria and other organisms that live inside the intestines.

Tiny hair-like projections that line the inside of the small intestine.

Packed into the abdomen in coils, the intestine offers a surface area for absorption far larger than its outward size suggests.

A substance that has been studied in the treatment of some types of cancer.

An herb native to islands in the South Pacific.

Within an artery (blood vessel that carries blood from the heart to tissues and organs in the body).

A type of radiation therapy used to treat liver cancer that is advanced or has come back.

The introduction of fluids and drugs directly into the carotid artery, the main artery in the neck that carries blood from the heart to the brain.

Within a cavity or space, such as the abdomen, pelvis, or chest.

A type of internal radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into a body cavity such as the chest cavity or the vagina.

Intracellular means located, occurring, or functioning inside a cell.

Intracolonic means located, occurring, or administered within the colon.

A tumor that occurs in the brain.

Intracutaneous describes an injection or process occurring within the layers of the skin itself, rather than beneath it or into muscle.

Intradermal describes an injection or finding located within the skin's layers rather than beneath it or on its surface.

A benign (not cancer), wart-like growth in a milk duct of the breast.

A noninvasive condition in which abnormal cells are found in the lining of a breast duct.

An intraductal papilloma is a benign, wart like growth within a breast milk duct that can cause nipple discharge.

Within the layer of cells that form the surface or lining of an organ.

Intrahepatic means located or occurring within the liver.

A bile duct that passes through and drains bile from the liver.

The delivery of anticancer drugs directly to the blood vessels of the liver.

Within an area of cancer, for example, within a tumor in the skin.

Intramuscular describes an injection given directly into muscle tissue, allowing medication to be absorbed into the bloodstream over a moderate period.