Glossary of Common Terms

Kidney and Urologic Terminology

The Dialysis Unit, part of the Division of Nephrology / Hypertension, provides patients and families with a glossary of kidney and urologic terminology.

Common Terms



A condition of excess buildup of acids in the bloodstream. See also renal tubular acidosis (RTA).

Alport Syndrome  

A form of hereditary nephritis that can result in chronic kidney disease and sensory loss.


A disorder marked by deposition of specific proteins (amyloid) in the body; see also primary amyloidosis, dialysis-related amyloidosis (DRA).


A condition marked by a deficiency of red blood cells or hemoglobin in the blood, resulting in paleness and weariness.


A large protein produced by the lymphocytes in the immune system in response to bacteria, viruses or other foreign substances in the body.


A natural body chemical that slows down the production of urine.


A condition in which the body stops producing urine.




A diagnostic test that involves collecting small pieces of tissue, usually through a needle, for examination under a microscope. A kidney biopsy can help find a diagnosis and determine the best course of treatment.



A tube that is inserted through an opening through which fluids may be added or removed.  A hemodialysis catheter inserts into a large vein to allow blood to be removed for dialysis, and other drugs / fluids may also be injected.  A PD catheter is inserted into the abdominal cavity and allows fluids to be inserted and drained to allow for dialysis.  A urinary catheter inserts through the urethra or other opening to drain urine from the bladder.

Childhood Nephrotic Syndrome  

A swelling condition caused by kidneys with damaged filters that may let protein leak into the urine. As a result of the blood's protein deficiency, water isn't absorbed and moves from the blood into body tissues to cause swelling.

Chronic Kidney Disease (CKD)  

Permanent loss of kidney function.

Continuous Ambulatory Peritoneal Dialysis (CAPD)  

Form of peritoneal dialysis that doesn't require a machine; the patient can move about with the dialysis solution in the abdomen.

Continuous Cycler-Assisted Peritoneal Dialysis (CCPD)  

Form of peritoneal dialysis that requires a machine called a cycler to fill and drain the abdomen, usually while the patient is asleep.


An abnormal pouch containing fluid.


A rare form of kidney stone consisting of the amino acid cystine; see also kidney stone.


Inflammation of the urinary bladder causing a pain or burning feeling in the pelvis or urethra.


A tube-like instrument used to look inside the urethra and bladder.


Procedure of bladder examination by insertion of a cystoscope into the urethra.



A condition characterized by high blood glucose (sugar) resulting from the body's inability to use glucose efficiently. In type 1 diabetes, the pancreas makes little or no insulin; in type 2 diabetes, the body is resistant to the effects of available insulin. The most common cause of kidney failure.

Diabetes Insipidus (DI)  

A rare form of diabetes caused by deficiency of the pituitary hormone vasopressin, which regulates kidney function. Causes frequent urination.


The clinical purification of blood as a substitute for the normal functions of the kidney; see hemodialysis, peritoneal dialysis (PD).

Dialysis-Related Amyloidosis  

A condition that occurs when a protein called Beta-2 Microglobulin builds up in the blood as a result of kidney malfunction. Beta-2 Microglobulin buildup can cause surrounding tissue damage and great discomfort.


End-Stage Renal Disease (ESRD)  

Total kidney failure; permanent loss of kidney function.


Involuntary urination, especially by children at night.


A hormone naturally produced by the kidney that increases red blood cell production by the bone marrow.



A passage between two organs or surfaces.  An arteriovenous (AV) fistula is a created connection between an artery and vein that can be stuck with needles to allow for hemodialysis.





A piece of material that is inserted into the body.  An arteriovenous (AV) graft is a piece of tubing, often made of GOR-TEX, which connects an artery to a vein and may be stuck with needles to allow for hemodialysis.


Describes the inflammation of the membrane tissue in the kidney that serves as a filter to separate wastes and extra fluid from the blood.


Describes the scarring or hardening of the tiny blood vessels within the kidney.

Goodpasture's Syndrome  

An autoimmune disease in which the immune system makes antibodies that attack the lungs and kidneys.



The presence of red blood cells (RBCs) in the urine.


The most common method used to treat advanced and permanent kidney failure. In hemodialysis, the blood is allowed to flow a few ounces at a time through a machine with a special filter that removes wastes and extra fluids. The clean blood is then returned to the body.

Hemolytic Uremic Syndrome (HUS)  

One of the most common causes of sudden, short-term kidney failure in children.


Swelling in the kidneys.


Swelling in the ureters.


An abnormally high level of phosphorus in the blood, often seen when kidney function starts to diminish and fail.


High blood pressure.


IgA Nephropathy  

Kidney disorder caused by deposits of the protein immunoglobulin A (IgA) inside the glomeruli (filters) within the kidney.


A loss of urinary control.

Interstitial Cystitis (IC)  

A condition that results in recurring discomfort or pain in the bladder and the surrounding pelvic region. Also known as painful bladder syndrome (PBS).




The two bean-shaped organs that filter wastes from the blood. The kidneys are located near the middle of the back. They create urine, which is delivered to the bladder through tubes called ureters.

Kidney Stone  

A hard mass developed from crystals that separate from the urine and build up on the inner surfaces of the kidney; see also nephrolithiasis.



A method of breaking up kidney stones using shock waves or other means.

Lupus Nephritis  

A glomerular disease; inflammation of the kidney caused by systemic lupus erythematosus (SLE), a disease of the immune system; see systemic lupus erythematosus (SLE).


Minimal Change Disease  

The most common form of the nephrotic syndrome in children.


Nephrogenic Diabetes Insipidus  

Constant thirst and frequent urination because the kidney tubules cannot respond to antidiuretic hormone. The result is an increase in urine formation and excessive urine flow.


The medical term for kidney stones; see also kidney stone.


The final stage of kidney disease; kidney failure.

Nephrotic Syndrome  

See childhood nephrotic syndrome.

Neurogenic Bladder  

Loss of bladder control caused by damage to the nerves controlling the bladder



Painful Bladder Syndrome (PBS)  

See interstitial cystitis (IC).

Peritoneal Dialysis (PD)  

A procedure for treating advanced or permanent kidney failure. In peritoneal dialysis, a soft tube called a catheter is used to fill the abdomen with a cleansing liquid called dialysis solution. The solution pulls wastes and extra fluid into the abdominal cavity. These wastes and fluid then leave the body when the dialysis solution is drained. See also continuous ambulatory peritoneal dialysis (CAPD), continuous cycler-assisted peritoneal dialysis (CCPD).


An inflammation, typically from bacterial infection, involving the peritoneal lining of the abdominal cavity and organs.

Polycystic Kidney Disease (PKD)  

A genetic disorder characterized by the growth of numerous cysts in the kidneys. The cysts can slowly replace much of the mass of the kidneys, reducing kidney function and leading to kidney failure.


A condition in which urine contains an abnormal amount of protein.


A kidney infection, commonly caused by bacteria that have spread from the bladder.




An immunologic attack against substances that the immune system recognizes as foreign, typically including transplanted organs.

Renal Agenesis  

A condition of birth with only one kidney.

Renal Osteodystrophy  

A bone disease that occurs when the kidneys fail to maintain the proper levels of calcium and phosphorus in the blood. Affects many (90 percent) of dialysis patients.

Renal Tubular Acidosis (RTA)  

A disease that occurs when the kidneys fail to excrete acids into the urine, which causes a person's blood to remain too acidic. Without proper treatment, chronic acidity of the blood leads to growth retardation, kidney stones, bone disease and progressive renal failure.


Systemic Lupus Erythematosus (SLE)  

A disease of the immune system, causing harm to the skin, joints, kidneys and brain.




A waste product found in the blood and caused by the breakdown of protein in the liver. Urea is normally removed from the blood by the kidneys and then excreted in the urine.


The condition of excessive amounts of urea in the blood.


Tubes that carry urine from the kidneys to the bladder.


The tube that carries urine from the bladder to the outside of the body.


Inflammation of the urethra.

Urinary Tract  

The system that takes wastes from the blood and carries them out of the body in the form of urine. Includes the kidneys, ureters, bladder and urethra.

Urinary Tract Infection (UTI)  

An infection anywhere in the urinary tract; see urinary tract.

Urodynamic Tests  

Measures of the bladder's ability to hold and release urine.


An opening through the skin into the urinary tract to allow urine to drain when voiding through the urethra is not possible.



To empty the bladder; to urinate.

Voiding Cystourethrogram  

An X-ray image of the bladder and urethra made during voiding. The bladder and urethra are filled with a special fluid to make the urethra clearly visible.

Vesicoureteral Reflux (VUR)  

The abnormal flow of urine from the bladder back into the ureters.