Medical terms A–Z

The main blood vessel that supplies blood to a kidney and its nearby adrenal gland and ureter.

The fibrous connective tissue that surrounds each kidney.

The most common type of kidney cancer.

The most common type of kidney cancer.

Renal cell carcinoma is the most common form of kidney cancer in adults, arising from the tubules that filter blood within the kidney.

The last part of a long, twisting tube that collects urine from the nephrons (cellular structures in the kidney that filter blood and form urine) and moves it into the renal pelvis and ureters.

A condition in which the kidneys stop working and are not able to remove waste and extra water from the blood or keep body chemicals in balance.

A fibrous envelope of tissue that surrounds the kidney.

A test in which blood or urine samples are checked for the amounts of certain substances released by the kidneys.

A tiny, round cluster of blood vessels within the kidneys.

The area at the center of the kidney.

A rare disorder in which structures in the kidney that filter the blood are impaired, producing urine that is more acid than normal.

The same molecule sold under another name for spots, put into a richer cream and aimed at sun-damaged skin instead.

Copying is never perfect, and the small rate of error is exactly what lets viruses and bacteria change over time.

In biology, refers to the reproduction cycle of viruses.

An egg or sperm cell.

The only body system that can be removed without ending a life, and the only one that stays switched off for years.

The organization that designs a trial and hands the protocol to the community sites that actually enroll people.

A scientific study of nature that sometimes includes processes involved in health and disease.

A resectable tumor or structure can be surgically removed based on its size, location, and relationship to nearby vital structures.

Resected describes tissue, an organ, or a growth that a surgeon has cut away and removed from the body during an operation.

Surgery to remove tissue or part or all of an organ.

A thin, tube-like instrument used to remove tissue from inside the body.

Cancer cells that remain after attempts to remove the cancer have been made.

Resin is a viscous substance, either plant derived or synthetic, applied in dentistry, pharmaceuticals, and manufacturing for its adhesive and binding properties.

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

Cancer that does not respond to treatment.

A process in which a substance, such as tissue, is lost by being destroyed and then absorbed by the body.

A respirator most often refers to a mechanical ventilator that supports breathing, though the same word also names a protective mask that filters inhaled air.

Respiratory failure names a measurement rather than a disease, so the same label covers a sedative overdose and end-stage lung disease alike.

Conducting airways carry air without exchanging any gas, and only the final branches of the tree do the actual work of respiration.

Largely a North American profession by this name, since elsewhere the same work is divided among physiotherapists, nurses and physicians.

One heading covers a nebulizer given for a few minutes and a ventilator running for weeks, so the phrase alone says nothing about intensity.

Most of its length does no gas exchange at all, which is why a shallow breath moves air without refreshing much of it.

The patient is not the only person being looked after here; the point of the arrangement is to give the regular caregiver a break.

A word doing two jobs: the body reacting to something, and the disease measurably changing after treatment.

The percentage of patients whose cancer shrinks or disappears after treatment.

Resting describes a cell that is temporarily inactive with respect to division, distinguishing it from one actively multiplying.

The hallmark of restless legs syndrome is an urge to move the legs that relieves an uncomfortable sensation, worsening at rest and in the evening.

An attempt to buy time rather than a treatment in itself, keeping blood moving while somebody works out why it stopped.

Resveratrol is a plant-produced antioxidant compound concentrated in grape skins and red wine, studied for potential cardiovascular and cancer related effects without established clinical use.

The action of the stomach and esophagus to try to vomit (eject some or all of the contents of the stomach).

The thick bottom layer of the dermis (the inner layer of the skin).

Retin-A is a brand name for topical tretinoin, a vitamin A derivative applied to skin to treat acne and reduce signs of photoaging.

A topical preparation of tretinoin that is used to treat acne.

The light-sensitive layers of nerve tissue at the back of the eye that receive images and sends them as electric signals through the optic nerve to the brain.

A childhood eye cancer usually noticed as a white glow in the pupil, and the tumor that revealed how cancer genes work.

The working form of vitamin A, a gene switch powerful enough that an excess of it deforms a developing embryo.

A retinoid is a compound chemically related to vitamin A, used in medicine to influence skin cell growth and, in some forms, cancer treatment.

Retinol is the storage and transport form of vitamin A, essential for vision, immune defense, and the normal growth of skin and other lining tissues.

A drug that is being studied in the prevention of cancer.

The small area behind the wisdom teeth.

Having to do with the area outside or behind the peritoneum (the tissue that lines the abdominal wall and covers most of the organs in the abdomen).

Surgery to remove the prostate through an incision made in the wall of the abdomen.

Retrospective describes research or review that looks backward at events, records, or outcomes that have already occurred.

A research study in which the medical records of groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and those who do not…

A study that compares two groups of people: those with the disease or condition under study (cases) and a very similar group of people who do not have the disease or condition (controls).

RNA from a virus that is used to insert genetic material into cells.

Genetic information running backward along its usual route, from RNA into DNA, and the step HIV cannot do without.

A tablet that leaves opioid receptors occupied but unstimulated, taking the reward out of both opioids and alcohol.

A chemical relative of thalidomide, redeveloped for cancer and now a mainstay of treatment for multiple myeloma.

An antiviral gene that is being studied in the treatment of cancer in patients who have HIV, the virus that causes AIDS.

A rare disease that damages the brain and liver and causes death if not treated.

A cancer vaccine made with a form of a chicken virus that does not cause disease in humans.

A substance being studied in the treatment of cancer.

A malignant tumor of either the central nervous system (CNS) or the kidney.

Rhabdomyosarcoma is a cancer of striated muscle tissue that can occur anywhere in the body but is most common in children.

Rheumatism is a broad, nonspecific term for pain and stiffness affecting joints, muscles, and related connective tissue, rather than a single diagnosis.

Stiffness that is worst on waking and eases with movement is the pattern separating it from ordinary wear on a joint.

A drug used to treat some types of cancer, rheumatoid arthritis, and severe skin conditions, such as psoriasis.

A drug used to increase the number of blood cells, especially platelets, in some cancer patients receiving chemotherapy.

The color and thickness of nasal discharge say far less about its cause than most people assume.

A thin, tube-like instrument used to examine the inside of the nose.

Examination of the inside of the nose using a rhinoscope.

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

A garden plant whose edible stalk and toxic leaf sit on the same stem, and whose dried root is a traditional laxative.

Ribavirin is a broad spectrum antiviral medication best known for treating respiratory syncytial virus infection and for use in combination regimens against hepatitis C.

Riboflavin, also called vitamin B2, is a water soluble nutrient the body needs to convert food into usable cellular energy.

The full chemical name behind the abbreviation RNA, covering every form the cell builds and not only the messenger kind.

A family of anticancer drugs that interfere with the growth of tumor cells by blocking the formation of deoxyribonucleotides (building blocks of DNA).

The molecular machine that reads a genetic message three letters at a time and builds the protein it specifies.

A rare condition in which chronic lymphocytic leukemia (CLL) changes into a fast-growing type of lymphoma.

A slow leukemia that has been quiet for years turning abruptly into an aggressive lymphoma, usually announced by one rapidly swelling node.

A substance being studied in the treatment of soft tissue and bone cancers.

A drug used to prevent the spread of a bacterium called in patients with advanced HIV (the virus that causes AIDS) infection.

Rifampin is an antibiotic most often used as a core component of combination treatment for tuberculosis and certain other mycobacterial infections.

A drug used to treat a nerve disease called amyotrophic lateral sclerosis (ALS).

A drug used to treat a nerve disease called amyotrophic lateral sclerosis (ALS).

Risedronate belongs to the bisphosphonate drug class and is an established medication for slowing bone loss and reducing fracture risk.

A statistical association, not a verdict: having one changes the odds without settling what will happen to any individual person.

A measure of the risk of a certain event happening in one group compared to the risk of the same event happening in another group.

The brand name is one of several for a single molecule, and what separates them is how fast and how long each releases it.

Ritonavir is a protease-blocking HIV medication now used mainly at low doses to boost blood levels of other antivirals rather than as a standalone treatment.

A ritual is a repeated, deliberate action or sequence of actions, which in a clinical context often refers to a compulsion in obsessive-compulsive disorder.

Stripping out B cells treats both a cancer of those cells and diseases in which the same cells drive an attack on the body.

Because CD20 is absent from stem cells and from antibody-producing plasma cells, the B cell population rebuilds and existing immunity is largely kept.

A substance that is being studied in the prevention of oral mucositis in patients receiving radiation therapy or chemotherapy for head and neck cancer.

A substance that is being studied for its ability to help other drugs reach the brain.

Best known as the messenger between gene and protein, RNA also stores the genes of many viruses and regulates the cell directly.

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