Medical terms A–Z

Beyond structural support, the skeleton stores minerals, produces blood cells within its marrow, and protects vital organs from injury.

One label covers several different diseases, and which cell a tumor came from matters far more than the fact that it sits in skin.

A change in the heat and electricity passed through the skin by nerves and sweat.

A skin graft transplants skin from one body site to another, replacing tissue lost to injury, surgery, or disease.

A bandage-like patch that releases medicine into the body through the skin.

The process of applying pressure, friction, temperature change, or chemical substances to the skin to lessen or block a feeling of pain.

A positive result proves the immune system remembers the substance, which is not the same as proving it causes symptoms.

Size is what separates this from a bulla, and depth is what decides whether it heals with a scar or without one.

Surgery to remove the top layer of skin of the vulva (the external female genital organs, including the clitoris, vaginal lips, and the opening to the vagina).

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

SLE is the abbreviation for systemic lupus erythematosus, an autoimmune disease in which the immune system attacks the body's own tissues.

A sleep disorder that is marked by pauses in breathing of 10 seconds or more during sleep, and causes unrestful sleep.

A disturbance of normal sleep patterns.

One of 5 parts or stages of the sleep cycle based on the type of brain activity that occurs during the stage.

Surgery to remove a lung tumor in a lobe of the lung and a part of the main bronchus (airway).

Surgery to remove a lung tumor in a lobe of the lung and a part of the main bronchus (airway).

Bark that turns slick and gelatinous in water, used traditionally to coat an irritated throat or gut.

An eye exam using an instrument that combines a low-power microscope with a light source that makes a narrow beam of light.

An eye exam using an instrument that combines a low-power microscope with a light source that makes a narrow beam of light.

An aggressive (fast-growing) cancer that forms in tissues of the lung and can spread to other parts of the body.

Small describes width rather than length, since this is by far the longest stretch of the digestive tract, several times the large intestine.

A rare cancer that forms in tissues of the small intestine (the part of the digestive tract between the stomach and the large intestine).

An indolent (slow-growing) type of lymphoma in which too many immature lymphocytes (white blood cells) are found mostly in the lymph nodes.

A group of diseases in which the bone marrow does not make enough healthy blood cells.

Myeloma already present in the marrow and visible in the blood, but not yet doing the organ damage that defines the disease needing treatment.

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

An anticancer drug that is also used in cancer prevention.

Millions of these single letter differences dot every genome, and only a small share change how a gene or its protein behaves.

A drug used in the treatment of chronic pain.

A substance being studied in the treatment of cancer.

A substance being studied in the treatment of cancer.

A substance being studied in the treatment of cancer.

A treatment plan is only as good as the ride to the appointment, and this is the part of care that supplies the ride.

A network of family, friends, neighbors, and community members that is available in times of need to give psychological, physical, and financial help.

Discharge from hospital frequently turns on housing, money and who will help at home, which is the territory a medical social worker occupies.

Sodium is an essential electrolyte that regulates fluid balance, nerve signaling, and blood pressure, distinct from table salt itself.

A substance used in a type of radiation therapy called boron neutron capture therapy.

A form of the mineral iron that is used to treat anemia caused by low amounts of iron in the blood.

A drug that is a type of nonsteroidal anti-inflammatory drug.

A substance being studied in the treatment of certain solid tumors, lymphoma, and myeloma.

A chemical used in photography, paper making, water treatment, and for other purposes.

One simple reaction, a sulfur atom loosely held and easily given away, explains a list of uses that otherwise looks unrelated.

A diet consisting of bland foods that are softened by cooking, mashing, pureeing, or blending.

The back, muscular (not bony) part of the roof of the mouth.

Refers to muscle, fat, fibrous tissue, blood vessels, or other supporting tissue of the body.

Soft tissue sarcoma is a rare cancer arising in muscle, fat, or connective tissue rather than in bone or organs.

A sun-damage lesion easier to feel than to see, and the visible tip of a much wider field of altered skin.

An abnormal mass of tissue that usually does not contain cysts or liquid areas.

A monoclonal antibody used to prevent red blood cells from being destroyed in patients with paroxysmal nocturnal hemoglobinuria (PNH), a red blood cell disorder.

A soluble substance dissolves in a given liquid, a property that determines how a compound is absorbed, formulated, or transported in the body.

A solvent is a liquid capable of dissolving another substance to form a uniform solution, a role relevant in pharmacy, laboratory work, and toxicology.

Somatic refers to the physical body, distinguishing bodily structures and symptoms from mental, emotional, or reproductive-cell processes.

Any of the body cells except the reproductive (germ) cells.

A DNA change acquired during life in one ordinary body cell, passed to its descendants but never to a child.

A protein made by the body that stimulates the growth of many types of cells.

A type of radionuclide scan used to find carcinoid and other types of tumors.

The pituitary's growth signal, released in bursts through the night and doing much of its work through a messenger from the liver.

Periods of drowsiness, lethargy, loss of appetite, and irritability in children following radiation therapy treatments to the head.

Sound bounces back wherever one tissue meets another, so the picture is assembled from echoes rather than from shadows.

Written so that the same task produces the same result whoever performs it, and so that anyone can later check that it did.

Sorafenib works through two separate mechanisms, directly slowing cancer cell growth while also limiting the blood supply a tumor depends on.

A drug used to treat advanced kidney cancer and a type of liver cancer that cannot be removed by surgery.

An antiviral drug that is being studied as a treatment for herpesvirus.

One name covering several sour tasting plants, which is why a recipe, a herbal label and a botany text can each mean something different.

A bean whose plant compounds resemble estrogen closely enough to be interesting and loosely enough to behave quite differently.

A product from a plant of Asian origin that produces beans used in many food products.

A legume unusual for supplying complete protein, and unusual again for containing plant compounds shaped like a human hormone.

A spasm is a sudden, involuntary muscle contraction that can affect a single muscle, a group of muscles, or the wall of an organ.

Depth in one area is bought at the cost of breadth, which is why general care usually continues alongside.

An immune cell such as a T or B lymphocyte that responds to a single, specific antigen.

When referring to a medical test, specificity refers to the percentage of people who test negative for a specific disease among a group of people who do not have the disease.

Often described as a type of CT scan, which it is not: the radiation comes from inside the patient, not from a tube.

Reading what a substance is made of by seeing which wavelengths it absorbs, emits or bends, since every material has a signature.

An instrument used to widen an opening of the body to make it easier to look inside.

A specialist who evaluates and treats people with communication and swallowing problems.

A specialist who evaluates and treats people with communication and swallowing problems.

The male reproductive cell, formed in the testicle.

Freezing sperm for use in the future.

A count of the number of sperm in a sample of semen.

Removal of sperm from a man's testis or epididymis by a doctor using a fine needle or other instrument.

A cord-like structure in the male reproductive system that contains nerves, blood and lymph vessels, and the vas deferens (a coiled tube that carries sperm out of the testicle).

A number describing how much more ultraviolet skin can take before burning, measured under laboratory conditions almost nobody reproduces.

Its position deep within the skull places the sphenoid sinus in close proximity to structures such as the pituitary gland and nearby nerves.

A ring of muscle whose resting state is closed, opening only when the body signals that something should pass.

A lump of tissue with spikes or points on the surface.

A temporary loss of feeling in the abdomen and/or the lower part of the body.

A temporary loss of feeling in the abdomen and/or the lower part of the body.

The bones, muscles, tendons, and other tissues that reach from the base of the skull to the tailbone.

A cable of nervous tissue about as thick as a finger, and considerably shorter than the bony canal that houses it.

Timing matters more than the size of the squeeze, since what a person can still do when treatment starts largely predicts what remains.

A spinal tap withdraws cerebrospinal fluid from the lower back using a thin needle, either to test the fluid or to deliver medication.

A type of cancer that begins in the skin or in tissues that line or cover internal organs and that contains long spindle-shaped cells.

A description of shape rather than a single disease, since many unrelated cancers look this way and shape alone cannot separate them.

The bones, muscles, tendons, and other tissues that reach from the base of the skull to the tailbone.

Spine cancer describes tumors of the vertebrae or spinal cord, though cancer reaching the spine from elsewhere is far more common than a primary tumor.

A detailed picture of areas inside the body.

A fist-sized filter tucked under the left ribs, sorting worn-out blood cells from good ones and screening blood for infection.

A splenectomy is a surgical procedure that removes all or part of the spleen, performed for injury, disease, or certain blood disorders.

Having to do with the spleen (an organ in the abdomen that makes immune cells, filters the blood, stores blood cells, and destroys old blood cells).

Splenomegaly is enlargement of the spleen beyond its expected size.