The words below are common terms used by dialysis and transplant patients.
For additional words and definitions, please refer to our Dictionary of Dialysis Terms (PDF).

Access
A means to reach the bloodstream. In Hemodialysis, fistulas, grafts, catheters, and subcutaneous vascular access’ are used.  Access to the peritoneal cavity for peritoneal dialysis is through a peritoneal catheter.

Acute Renal Failure
A condition in which the kidneys suddenly stop working. In many cases, kidneys can recover.

Adequacy
The amount of dialysis to prevent uremic symptoms. In hemodialysis, this is measured by Kt/V and URR. In peritoneal dialysis, this is measured by Kt/V and Creatinine Clearance.

Albumin
One of a class of proteins in the blood. A reduced level of albumin may be a sign of inadequate protein intake in the diet.

Anemia
A common condition in patients with kidney disease, which there are not enough red blood cells in the blood to carry oxygen. Anemia is often referred to as “low blood” and causes weakness and fatigue.

Anticoagulant
A substance that is given to prevent clotting of the blood (example: Heparin).

Anuria
A condition in which a person stops making urine.

Arterial Line
The tube carrying blood from the body into the artificial kidney (dialyzer).

Arteriovenous Fistula
Surgical connection of an artery directly to a vein, usually in the forearm, created in patients who will need hemodialysis. The AV fistula causes the vein to grow thicker, allowing the repeated needle insertions required for hemodialysis.

Artificial kidney
Another name for a dialyzer.

Bath
Another name for dialysate fluid, which is a clean salt-containing solution.  Inside the dialyzer waste products will flow from the blood into the dialysate and are then washed away.

Blood Flow Rate (BFR) or QB
The amount of blood passing through the artificial kidney (dialyzer) each minute. This is determined by the speed at which the blood pump is set.

Blood Pump
A pump that is used to bring blood from the patient and push it through the artificial kidney or dialyzer and back to the body.

Blood Urea Nitrogen (BUN)
A waste product, or toxin, that appears in the blood as protein from food is digested. BUN levels are a measure of how well the kidneys are functioning as well as adequacy of dialysis and nutritional status. A high BUN indicates that the kidneys are not removing enough waste.

Bloodlines
The arterial line and venous line used in hemodialysis.

Bruit
The sound of blood moving through a fistula or graft that indicates that the access is working.

Cannulation
The process of inserting a needle into the graft or fistula.

Catheter
A tube inserted through the skin into a blood vessel or body cavity to draw out blood or body fluids, or to put in fluid. In peritoneal dialysis, a catheter is used to instill dialysis solution into the abdominal cavity and drain it out again. In hemodialysis, a catheter in a vein can be used to create a temporary or longer-term dialysis access.

Centers for Medicare & Medicaid Services (CMS)
(formerly known as HCFA – Health Care Financing Administration) The department of the federal government that oversees the Medicare and Medicaid programs.

Chronic Renal Failure (CRF)
Slow and progressive loss of kidney function over several years, often resulting in End Stage Renal Disease.

Clotting time
The time it takes the blood to form a clot.

Conductivity
The measure of ions in a solution. A conductivity meter measures the chemical composition of dialysate by measuring the dialysate’s ability to conduct an electrical current.  If the conductivity of dialysate is not correct an alarm will go off, and the dialysate is bypassed to the drain. This means the dialysate will not come in contact with the patient’s blood.

Continuous Ambulatory Peritoneal Dialysis (CAPD)
A type of dialysis where the patient’s peritoneal membrane is used as the dialyzer. The patient dialyzes at home, using special supplies, but without the need for a machine. When you are on CAPD, you change the fluid in your peritoneal cavity by doing what is called "an exchange". This can be performed in any clean and convenient place - at home, at work, at school or on vacation. The exchanges use gravity to drain the used fluid out of the peritoneal cavity and to replace it with fresh fluid. Most CAPD patients need to do about 3 to 5 exchanges a day. (See Peritoneal Dialysis)

Continuous Cycling Peritoneal Dialysis (CCPD)
A type of dialysis where the patient dialyzes at home and uses a machine which automatically delivers cycles of dialysis exchanges. A typical CCPD schedule involves three to five exchanges during the night while the person sleeps. One or more additional exchanges may also be performed during the daytime. (See Peritoneal Dialysis)

Creatinine
A waste product released from the muscles of the body. Creatinine is normally removed from the blood by the kidneys.

Creatinine Clearance
A test that measures how well the kidneys remove creatinine from the blood. A decreased creatinine clearance reading means decreased function of the kidneys.

Dialysate / Dialysate fluid
Also called bath. The solution used to remove excess fluids and waste products from the blood.

Dialysate Flow Rate (DFR) or QD
The rate at which dialysate fluid moves through the dialyzer.

Dialysis
The process of cleaning wastes from the blood artificially. This job is normally done by the kidneys. If the kidneys fail, the blood must be cleaned artificially with special equipment. The two major forms of dialysis are hemodialysis and peritoneal dialysis.

Dialyzer (artificial kidney)
An artificial kidney used with the hemodialysis machine. The dialyzer has two sections separated by a membrane. One section holds dialysate fluid and the other holds the patient’s blood. Waste products and fluid travel from the blood in to the dialysate fluid, across the dialyzer membrane, and are disposed of.

Dry Weight (ideal weight) (target weight)
The weight at which all excess fluids have been removed.

End Stage Renal Disease (ESRD)
Any irreversible kidney disease that requires dialysis therapy or kidney transplant in order to live. The term “end-stage” means that the renal disease is permanent and irreversible, and not that the person’s condition is terminal.

Erythropoietin
A hormone which stimulates the body to produce red blood cells. It is normally produced in the kidney, but with renal failure the body cannot produce this hormone, resulting in anemia.

ESRD Networks
The ESRD Networks were established by the U.S. Government in 1978 to oversee dialysis and transplant facilities and ensure that patients receive high quality care. The Networks collect data, oversee quality improvement activities, encourage rehabilitation, establish a grievance procedure for patients, and provide resource materials to ESRD staff and patients.

Fistulogram
A special procedure performed in the Radiology Department of a hospital.  With the use of X-ray dye, the blood flow through a fistula will be evaluated. The procedure can detect problems such as a clot or narrowing. Early detection and treatment of problems with a fistula can improve its performance and limit future complications.

Fluid Overload
Excess sodium (salt) and fluid retained in the body between dialysis treatments; may cause shortness of breath and swelling.

Fluid Restriction
The amount of fluid a patient is allowed to drink in a 24-hour period to avoid adding extra weight that would cause fluid overload and undue stress to the heart.

Hemodialysis
The use of a machine to clean wastes from the blood after the kidneys have failed. The blood is circulated through tubes to a dialyzer, which removes wastes and extra fluid.  The cleaned blood is returned in another set of tubes back into the body.

Hemoglobin
The substance in red blood cells that carries oxygen around the body. Low hemoglobin suggests anemia or increased blood loss.

Heparin
A medication that prevents the blood from clotting too quickly.

Infiltration
The leakage of a substance into body tissues. In hemodialysis patients, infiltration of blood into the tissues surrounding the access can occur if the needle punctures the back of the vessel wall or is partially dislodged from the access.

Kidney Failure
The loss of kidney function. (See also End Stage Renal Disease)

Kidney Transplantation
The replacement of a diseased kidney with a healthy one.

Kidneys
The two bean-shaped organs located on either side of the spine, just above the waist. They rid the body of waste materials and maintain fluid balance through the making of urine.

Kt/V
A measurement of how much urea is being removed from the blood during dialysis. The measurement takes into account the efficiency of the dialyzer, the treatment time, and the total amount of urea in the body.

Membrane
A thin sheet or layer of tissue that lines a cavity or separates two parts of the body. A membrane can act as a filter, allowing some particles to pass from one part of the body to another while keeping others where they are. The artificial membrane in a dialyzer filters waste products from the blood.

National Kidney Foundation (NKF)
A voluntary health organization which seeks to prevent kidney and urinary tract diseases, improve the health and well-being of individuals and families affected by these diseases, and increase the availability of all organs for transplantation.

Nephrologist
A medical doctor who treats patients with kidney problems or hypertension.

Osmosis
Passing of fluid through a semipermeable membrane from a solution with a low solute concentration to a solution with a higher solute concentration until there is an equal concentration of fluid on both sides of the membrane.

Patent
Unblocked flow of blood in a blood vessel, graft, or catheter.

Peritoneal Dialysis
A treatment for kidney failure in which dialysate is put into the peritoneal cavity. The dialysate causes waste and excess water to be drawn across the peritoneal membrane into the cavity.  When the process is complete, the fluid is drained off and replaced.

Peritonitis
Infection in the peritoneal cavity usually treated with antibiotics.

Potassium
An essential chemical salt in the body that regulates heart and muscle movement. High or low levels in the blood may cause muscle weakness and cause the heart to stop.

Renal
Having to do with, or referring to, the kidneys.

Renin
A hormone produced by the kidney which helps regulate the volume of fluid in the body and blood pressure.

Rinseback
The process of using saline to flush the patient’s blood back into the body from the dialysis tubing after dialysis.

Saline
A salt solution containing sodium and chloride.

Semipermeable Membrane
A material through which only certain particles may pass, and to which other particles cannot pass.

Staff-assisted dialysis
Dialysis performed by the staff of the renal dialysis center or facility.

Shunt
Another word for fistula or graft.

Thrill
The buzzing sensation that can be felt by touching a fistula or graft. This indicates that the access is working.

Toxins
Waste products that accumulate in the blood of ESRD patients that are usually harmful to the body.

Transplant
The replacement of a diseased organ with a healthy one.

Trendelenburg position
A body position in which the head is placed at 45 degrees with the legs up (feet above the head). This position helps when a person has hypotension.

Ultrafiltration
The process of removing excess water from the blood during dialysis.

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

Urine
Liquid waste product filtered from the blood by the kidneys, stored in the bladder, and expelled from the body through the urethra by the act of voiding or urinating.

URR (Urea Reduction Ratio)
A blood test that compares the amount of blood urea nitrogen (BUN) before and after dialysis to measure the effectiveness of the dialysis prescription.

Vein
A blood vessel that carries blood toward the heart.

Venous Line
The tube carrying the blood back into the body from the artificial kidney machine.

Vital Signs
Blood pressure, temperature, pulse, and respiratory rate.

For additional words and definitions, please refer to our Dictionary of Dialysis Terms (PDF).