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Kidney health glossary


Words you may need to know

Get a better understanding of some of the common terms related to chronic kidney disease (CKD) and end-stage renal disease (ESRD). This will help you better understand your condition and feel more confident talking to your doctor.

Automated peritoneal dialysis

A type of dialysis that uses your abdomen to clean your blood. Peritoneal dialysis is a type of dialysis which uses the peritoneum in a person's abdomen as the membrane through which fluid and dissolved substances are exchanged with the blood. 

This method uses a machine (an automated cycler) that performs multiple fluid exchanges at night while you’re sleeping. The cycler automatically fills your abdomen with a cleansing fluid (dialysate). It allows it to stay there and then drains it into a sterile bag that you empty the next morning.

Blood urea nitrogen (BUN)

A BUN test measures the amount of nitrogen in your blood that comes from a waste product called urea. Urea nitrogen is a waste product made when your liver breaks down protein. The test is done to show how well your kidneys are working.


A mineral that’s found in your bones. It keeps your bones healthy and helps with muscle contraction, heart function and blood clotting.

Catheter (hemodialysis)

A type of hemodialysis vascular access. A thin tube is inserted into a vein, usually below the right collar bone by surgery. It creates a pathway for your blood to go from your body to a dialysis machine and back to your body.

Catheter (peritoneal dialysis)

A soft plastic tube that’s placed in your abdomen by surgery. It creates a pathway for the peritoneal dialysis fluid to flow in and out of your body.

Chronic kidney disease (CKD)

The condition of gradual loss of kidney function. With CKD, your kidneys can’t filter wastes and extra fluids from your blood the way they typically would.

Conservative care/Supportive care

A treatment option for chronic kidney disease when you decide to continue your care without dialysis or a transplant.

Continuous ambulatory peritoneal dialysis (CAPD)

A type of peritoneal dialysis that’s done by hand and is machine-free. It works by placing about two quarts of dialysate fluid into your abdomen and later draining it. You do this by hooking up a plastic bag of dialysate fluid to the tube in your abdomen.

Gravity moves the fluid through the catheter and into and out of your abdomen. People may need three to four exchanges each day with this method.


A waste product from the breakdown of muscles. It’s measured using a blood test and shows how well your kidneys are working.


A machine that delivers and drains the peritoneal dialysis fluid to your body.


A procedure that filters waste products and extra fluids from your blood using a machine, or can be performed manually in peritoneal dialysis. It’s one of the main treatments for kidney failure.

Dialysis center

A place that offers dialysis treatment in their facility or supports and coordinates treatment at home.


A sterile solution that removes fluid and waste from your blood.


A special filter used with a dialysis machine.

Dwell time

The time after the sterile peritoneal dialysis fluid is put into your abdomen. This may be several hours.

Early transplant

Getting a transplant not long after kidneys fail, but with some time on dialysis.

End-stage renal disease (ESRD)

End-stage kidney disease (ESKD)

Kidney failure/Stage 5 kidney disease

A medical condition in which a person’s kidneys stop functioning, leading to the need for regular, long-term dialysis or a kidney transplant to maintain life.

Estimated glomerular filtration rate (eGFR)

A calculated estimate of how well your kidneys are working and helps determine the stage of kidney disease. It’s calculated using the results of your blood creatinine test and your body size, age and gender.


The process of putting the peritoneal dialysis fluid into the abdomen, letting it sit for a certain amount of time and draining it. Each time the process is done is called an exchange or cycle.


A type of vascular access. It’s a connection that’s made under the skin between your natural artery and vein. It creates a pathway for your blood to go from your body to the dialysis machine and then back to your body.


A cluster of small blood vessels where waste products are filtered from the blood. It’s one of the two parts of the nephrons.

Glomerular filtration rate (GFR)

A test to measure kidney function. It shows how well your kidneys are working.


A type of vascular access. It’s a man-made tube that’s inserted under the skin to connect an artery to a vein. It creates a pathway for your blood to go from your body to the dialysis machine and then back to your body.


A type of dialysis where the blood is filtered through a dialyzer on a dialysis machine and then returned to your body. You can have this type of treatment at home or in a dialysis center.

Home hemodialysis

This is when you perform hemodialysis in your own home.

Hospice care

A support program for people who are at the end of life.

In-center dialysis

A facility where people go to have hemodialysis treatments.


A doctor who has special, advanced training in caring for people with kidney disease. They can also help you make decisions about dialysis or kidney transplant.

Nephrology nurses

Registered nurses (RNs) or licensed practical nurses (LPNs)/licensed vocational nurses (LVNs) who specialize in caring for people with kidney disease.


Filtering units in the kidneys. Each unit contains the glomerulus and tubule. They work together to clean the blood.

Nurse practitioners and physician assistants

Health care professionals with advanced degrees and training who work closely with you, your doctor and your health care team to coordinate your overall care.

Palliative care

Specialized medical care given to improve the quality of life in people who have a serious or life-threatening disease. It addresses the person as a whole, not just their disease.


Transportation for people with disabilities who are unable to use the regular, fixed-route transit services.

Patient care technicians

Trained health care professionals under the supervision of doctors and nurses, who start your treatment, check blood pressure and monitor your care at the dialysis center.

Peritoneal dialysis

A type of dialysis that uses your peritoneum (abdominal lining of your belly) as the filter.


A thin sac that forms a lining around the abdominal organs in your belly.


A mineral found in your bones. Along with calcium, it builds healthy bones and keeps other parts of your body healthy.


A mineral that helps your heart and muscles function properly.

Preemptive transplant

Getting a transplant before starting dialysis.

Primary care provider

A doctor who works with you and your care team to coordinate your overall care. They also help you take care of other conditions that can complicate kidney disease, like diabetes and high blood pressure.

Renal arteries

Arteries that supply the kidneys with blood. They carry a large portion of total blood flow to the kidneys.

Renal dietitians

Health care professionals who specialize in diet and nutrition. They work closely with you to create healthy, kidney-friendly meal plans.

Renal replacement therapy

Therapy that replaces the typical blood-filtering function of the kidneys. It’s used when the kidneys aren’t working well and includes dialysis and transplant.

Social workers

Trained professionals who can help you lead a fuller, healthier life. They also help you find local, state and federal resources.


A mineral found in most of the foods we eat. It helps manage the water balance in your body.

Supportive care/Conservative care

A treatment option for CKD when you decide to live your life without dialysis or a transplant.


This is the doctor who performs surgery, including creating vascular access (graft or fistula) or places your catheter into your body. They’ll check to make sure your access is healthy throughout your course of dialysis and address any problems.


A treatment option for ESRD. Through surgery, a doctor will place a healthy organ into your body. A transplant can come from a live donor, like a partner, friend or relative, or from a deceased donor who donates their organs after death.

Treatment plan

A plan of medical care to help you get well, or to keep an illness or disease from getting worse.


A small tube in the kidney that contains cells that filter and clean the blood. It’s one of two parts of the nephron.

Vascular access

A pathway for your blood to go from your body to the dialysis machine and back to your body. The three types of vascular access are catheter, fistula and graft.


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