Kidney Disease Glossary

Access

In dialysis, this is the word used for a pathway into the body. For hemodialysis, the access leads to the bloodstream (see Vascular Access). For peritoneal dialysis, a plastic catheter will be placed in the belly or chest to reach the abdomen, which is lined with many small blood vessels.

ACE inhibitor

Angiotensin (an-gee-oh-TEN-sin) Converting Enzyme inhibitor. This type of blood pressure pill works by keeping the body from making the hormone angiotensin. This hormone makes the blood vessels constrict, which raises blood pressure. A doctor may prescribe it to help slow kidney damage.

Acute renal failure

Sudden kidney failure. Often, the cause of acute renal failure is an injury that reduces blood flow to the kidneys, or a response to a drug or poison. Someone who survives acute kidney failure may get kidney function back, or may go on to chronic kidney failure.

Adequacy (ADD-ih-kwah-see)

The dose of dialysis needed to prevent uremia (a build up of toxins in the blood).

Albumin (al-BYOO-min)

A form of protein in the blood. A late symptom of chronic kidney disease can be that protein foods like meat, fish, or chicken don’t taste good or that you don’t want to eat them. It is vital to eat enough protein to avoid malnutrition: but not so much that it puts more stress on the kidneys. A dietitian can help sort out how much protein is the right amount.

Albuminuria(al-BYOO-min-UR-ee-ah)

Presence of the protein albumin in the urine. Protein is a large molecule that healthy kidneys keep in the body. Having protein leak into the urine is a sign that the kidneys may not be working as they should.

Amyloidosis (am-ill-oy-DOH-sis)

See Dialysis-related Amyloidosis.

Anemia

A shortage of red blood cells, which bring oxygen to all of the body’s cells and tissues. Symptoms include feeling tired, short of breath, weak, cold all the time, and having pale skin, gums, and nail beds. Anemia is very common in chronic kidney disease, because healthy kidneys make the hormone erythropoietin (see EPO) that tells the body to make red blood cells.

ARBs­

Angiotensin Receptor Blocker. This type of blood pressure pill works by blocking the action of the hormone angiotensin (which raises blood pressure). A doctor may prescribe it to slow down kidney damage.

Arteriovenous (ar-TEER-ee-oh-VEE-nuss) fistula (FIS-choo-lah)(AVF)

The best type of vascular access for hemodialysis. An AVF is made when a surgeon sews together an artery and a vein beneath the skin, most often in an arm. The force of blood flow from the artery makes the vein large and thick enough to be used for dialysis. At each treatment, two needles are placed in the AVF, one to take the blood to the dialyzer and one to bring it back. AVFs are less likely to become clotted or infected than any other type of access.

Arteriovenous (ar-TEER-ee-oh-VEE-nuss) graft

A form of vascular access for hemodialysis. A graft is made when a surgeon uses a piece of artificial vein to connect an artery and a vein beneath the skin. At each treatment, two needles are placed into the artificial vein (graft), one to take the blood to the dialyzer and one to bring it back. Care must be taken to avoid placing the needles in exactly the same place each time, or the graft will tear and need to be replaced.

Artery

A blood vessel that carries oxygen-rich blood (bright red) away from the heart to other parts of the body.

Automated peritoneal (PARE-ih-ton-EE-ahl) dialysis (APD)

A form of peritoneal dialysis that is done at home. Sterile fluid is placed into the abdomen through a catheter. A cycler machine drains and refills the abdomen a few times each night during sleep. A daytime exchange may also be needed. Also called continuous cycling peritoneal dialysis (CCPD). The dialysis center provides the cycler, training, and 24-hour phone back-up.

Binders

(See phosphate binders).

Biopsy

To remove a small sample of tissue or organ for testing.

Bladder

The balloon-shaped organ where urine collects before it is passed out of the body. Located in the pelvis.

Blood Urea (yoo-REE-uh) Nitrogen (BUN)

A measure of the amount of urea (a nitrogen waste) in the blood. Healthy kidneys remove urea from the blood (normal range for adults is 7-20 mg/dL). If the kidneys don’t work, the urea level in the blood (BUN) will go up. BUN is used to measure how well dialysis removes wastes from the blood.

Bruit

(BROO-ee) “Whooshing” sound blood makes as it flows through a dialysis fistula or graft.

Calcium

A mineral stored in the bones and needed to maintain strong bones and teeth. Calcium also aids blood clotting, and the function of muscles (including the heart) and nerves. Calcium is found in dairy (milk, cheese, and yogurt), some vegetables, or supplements.

Catheter

A tube that lets fluids flow into or out of the body. A catheter may be placed in the chest (presternal) or abdomen for peritoneal dialysis. Or, a catheter may be placed in a large central vein in the neck or chest for hemodialysis.

Chronic kidney disease (CKD)

A slow loss of kidney function over time. CKD can lead to kidney failure and the need for dialysis or a kidney transplant. Most of the time, once the damage occurs, it can’t be reversed—but it can be slowed or stopped with treatment. There are 5 stages of CKD, from stage 1 (mild) to stage 5 (permanent kidney failure).

Congestive Heart Failure (CHF)

The heart can’t pump as much blood as the body needs. Some causes of CHF affect the right side of the heart; some affect the left. In kidney disease, the left side of the heart may work too hard if there is too much fluid in the body. It can become enlarged and flabby, taking up space that is needed for blood. Signs and symptoms of CHF include shortness of breath and swelling in the hands, feet, and ankles.

Continuous Ambulatory Peritoneal (PARE-ih-ton-EE-ahl) Dialysis (CAPD)

A form of peritoneal dialysis that is done at home. Sterile fluid is placed into the abdomen through a catheter. The fluid remains for a few hours while wastes and extra fluid from the blood flow into it. Then the used fluid is drained out and fresh fluid is put in. An “exchange” of fluid takes about half an hour, and is done 4-5 times each day.

Continuous Cycling Peritoneal (PARE-ih-ton-EE-ahl) Dialysis (CCPD)

A form of peritoneal dialysis that is done at home. Sterile fluid is placed into the abdomen through a catheter. A cycler machine drains and refills the abdomen a few times each night during sleep. A daytime exchange may also be needed. Also called automated peritoneal dialysis (APD).

Creatinine (kree-AT-ih-nin)

A waste product that forms each time you move your muscles. It is removed by healthy kidneys. High levels of creatinine in the blood may be a sign that the kidneys are not working as well as they should.

Creatinine (kree-AT-ih-nin) clearance

A test that measures how well the kidneys are removing creatinine from the blood. If the creatinine clearance is low, the kidneys may be damaged.

CT scan

Computerized tomography (CT) is a type of X-ray that can be used to make a moving picture of the kidneys.

Cycler

A small machine used to instill and drain dialysis fluid from the abdomen for a type of peritoneal dialysis (called APD or CCPD). The dialysis center provides the cycler, training, and 24-hour phone back-up.

Daily home hemodialysis

See short daily hemodialysis.

Diabetes (diabetes mellitus)

A chronic disease that leads to high levels of blood sugar. Type 1 is an autoimmune disease that destroys the islet cells in the pancreas that make insulin. Type 2 is a lifestyle disease where the body does not have enough insulin for the amount of sugar and starch that are eaten, or the cells won’t let the insulin in. Type 2 diabetes is the number one cause of chronic kidney disease.

Dialysis (dye-AL-ih-sis)

Dialysis is a treatment that removes wastes and fluid from the blood of people whose kidneys have failed. There are many ways to do dialysis, at home or in a center. The choice of a dialysis type affects energy level, ability to keep a job, number of medicines needed, and whether the diet or fluid intake must be strictly limited.

Dialysis-related Amyloidosis (DRA)

Build-up of a protein called beta-2-microglobulin (B2m) in the soft tissues, bones, and joints of people who have been on dialysis for a long time. It can cause pain in the joints and/or bones.

Dialyzer (DYE-uh-lye-zer)

A plastic filter or “artificial kidney” used for hemodialysis. Dialyzers are filled with hollow fibers. Blood flows through the inside of the fibers, and a special fluid bathes the outside. Wastes and fluid from the blood flow through pores in the fibers and into the fluid, where they are washed away.

Diuretic (dye-yur-REH-tick)

A “water pill” that causes the body to make more urine. Diuretics are often the first choice for helping to lower high blood pressure.

Dwell time

The length of time that dialysis fluid is left in the abdomen before it is drained out and exchanged for new fluid in peritoneal dialysis.

Edema (eh-DEE-muh)

Swelling caused by too much fluid in the body. Many people notice the swelling in their hands, feet, ankles, and under their eyes.

eGFR

Estimated glomerular filtration rate. This is a measure of how well the filters in your kidneys (glomeruli) are working. To calculate eGFR, you need to know someone’s age, gender, race, and creatinine level.

End-Stage Renal Disease (ESRD)

Stage 5 chronic kidney disease, or permanent kidney failure. At this point, the kidneys don’t work well enough to keep a person alive, so dialysis or a kidney transplant is needed.

EPO

Abbreviation for the hormone erythropoietin. (See erythropoietin.)

Erythropoietin (eh-rith-row-POH-eh-ton) (EPO)

A hormone made by healthy kidneys that tells the bone marrow to make red blood cells. Damaged kidneys don’t make enough EPO. A shortage of EPO leads to anemia, which can be treated with injections of a bioengineered form of the hormone.

Exit site

The place where a peritoneal dialysis catheter comes out of the body. The exit site must be kept clean and watched for signs of infection like redness or swelling.

Exchange

The process of draining out used peritoneal dialysis fluid and replacing it with fresh fluid.

Fistula (FIS-choo-lah)

See Arteriovenous fistula

Fluid overload

Extra fluid in the body that causes problems like swelling or shortness of breath. Over the long term, fluid overload makes the heart work harder and can lead to heart failure.

GFR

Glomerular filtration rate. A measure of how well the kidneys are working. (See eGFR)

Glomerulonephritis (gloh-MARE-yoo-low-nef-RYE-tiss)

Inflammation of the tiny filters in the kidneys called glomeruli. It can be caused by infection or an immune system reaction and can lead to kidney failure.

Glomerulus (gloh-MARE-yoo-luss)

A tangled ball of tiny blood vessels in the nephron of the kidney where water and wastes are filtered from the blood. There are more than one million in each kidney. The plural is glomeruli.

Graft

See Arteriovenous graft

Hematocrit (hee-MAT-o-krit) (Hct)

A test of the percent of blood that is made up of red cells. This test is used to see if anemia is present.

Hematuria (hee-muh-TUR-ee-ah)

Blood in the urine. This can be a sign of kidney stones or other kidney problems.

Hemodialysis

A treatment that removes wastes and excess water from the blood by passing it through a dialyzer. Water and wastes flow out of the blood through the hollow fibers in the dialyzer and into a special fluid. The person’s blood is brought to the dialyzer and back through tubing connected to needles placed into a vascular access. Hemodialysis can be done at home or in a dialysis center, during the day or at night during sleep.

Hemoglobin (HEEM-ah-gloh-bin) (Hgb)

The red, oxygen-carrying pigment of red blood cells. Hemoglobin levels are tested to see if anemia is present and to follow the response to anemia treatment.

High blood pressure

Blood pressure that is often higher than 140 over 90 mmHg. Causes include too much fluid in the body, narrowing of the blood vessels, or too much of the hormone renin (which is made by the kidneys). There may be no symptoms. High blood pressure is the number two cause of chronic kidney disease. It can also be caused by kidney disease. High blood pressure can often be controlled with pills.

Hypertension

High blood pressure.

In-center hemodialysis

Hemodialysis treatments done in a dialysis clinic (center). Standard treatments are done for 3-4 hours three days a week (MWF or TRS). Nocturnal in-center treatments are done at night during sleep three nights per week, leaving days free for work or other activities. Nocturnal treatments remove more fluid and wastes, which feels more like having healthy kidneys.

Inflammation

Redness, swelling, warmth, and pain that form the body’s response to injury (like infection or irritation).

Iron

A mineral that carries oxygen in the body. It is part of the hemoglobin in red blood cells. A lack of iron can cause anemia.

KDOQI (kay-DOH-key)

Kidney Disease Outcomes Quality Initiative. A national effort by kidney disease experts to study, report on, and improve treatment of chronic kidney disease. Begun in 2000, the group has written clinical practice guidelines on many topics. The National Kidney Foundation publishes the guidelines.

Kidneys

Two bean-shaped organs found in the small of the back on either side of the spine. Kidneys keep homeostasis (balance) in the body by controlling levels of water and chemicals in the blood. The kidneys also make hormones that control the number of red blood cells in the body and allow the gut to absorb calcium from food.

Kt/V(kay-tee-over-VEE)

A formula used to measure the dose of dialysis based on removal of urea. K is the clearance of the dialyzer. T is treatment time. V is the volume of water in the body. For hemodialysis, Kt/V should be at least 1.2. For peritoneal dialysis the weekly Kt/V should be at least 2.0.

Microalbuminuria (MY-kro-al-BYOO-min-UR-ee-ah)

Very small amounts of the protein albumin in the urine. This can be an early sign of kidney damage, especially in people who have diabetes (who should have this test done once a year.)

Modality (moh-DAL-ih-tee)

A treatment option. The modalities for treating chronic kidney failure are hemodialysis (at home or in a center), peritoneal dialysis (by hand or with a cycler), kidney transplant, and no treatment.

MRI

Magnetic resonance imaging. Use of powerful magnets lined up by radio waves to form a picture of the soft tissues and internal organs.

Nausea

The feeling of being “sick to your stomach,” or like you are going to vomit.

Nephritis (nef-RYE-tiss)

Inflammation of the kidney.

Nephrologist (nef-RAHL-ah-jist)

A doctor who specializes in the treatment of diseases of the kidneys.

Nephrology (nef-RAHL-ah-gee)

The medical study of the kidneys and kidney diseases.

Nephron (NEF-ron)

The basic functional unit of the kidney to remove waste and fluid. Each kidney has about one million nephrons.

Nephropathy (nef-RAH-pah-thee)

Disease of the kidney.

Neuropathy (nur-RAH-pah-thee)

Nerve disease. This is a common complication of diabetes or uremia. Over time, not getting enough dialysis can lead to nerve damage. Symptoms may include burning, tingling, and numbness, especially in the feet, lower legs, and hands.

Nocturnal hemodialysis

Hemodialysis done for 8 hours during sleep, leaving days free for work or other activities. Treatments are done 3-6 nights per week. The long treatments mean fluid is removed gently, which is easy on the heart. More wastes are removed, too. Most people who do nocturnal hemodialysis need no diet and fluid limits. Fewer medicines are needed. When treatments are done at home, most programs require a helper to be on hand. The dialysis center provides the machine, training, and 24-hour phone back-up.

NSAIDs

Non-steroidal anti-inflammatory drugs. These are used to reduce pain, fever, and swelling, but can damage the kidneys if taken often or in large doses. NSAIDs should be taken with a full glass of water in people who have kidney function. The chance of kidney damage is much higher if someone is dehydrated.

Parathyroid glands

Small endocrine glands found inside the thyroid gland (in the neck). They make parathyroid hormone (PTH), which controls levels of calcium and phosphorus in the blood. If these levels are not kept constant, the glands can enlarge and surgery may be needed to remove them.

Peritoneal (PARE-ih-ton-EE-ahl) dialysis (PD)

A type of home dialysis that uses the uses the membrane lining the inside of the abdomen (peritoneum) as a filter to clean the blood. Sterile fluid (dialysate) is placed in the abdomen through a catheter. Extra water and wastes move from blood vessels in the peritoneum into the fluid. Then the used fluid is drained and replaced with fresh.

Peritoneum (PARE-ih-ton-EE-um)

Membrane that lines the abdominal cavity and surrounds the internal organs.

Phosphate binder

A pill or capsule taken with meals that works like a magnet to pull excess phosphorus from the body and remove it in the stool. Taking phosphate binders can help keep bones strong and healthy and avoid the need to remove the parathyroid glands in the neck.

Polycystic (polly-SIS-tick) kidney disease (PKD)

A genetic disease that causes small, fluid-filled cysts to form in the kidneys, so they don’t work properly. PKD runs in families, and often leads to chronic kidney failure.

Potassium

A salt the body needs for normal muscle and nerve function, and to keep cells healthy. Levels of potassium that are too high or too low can cause illness or sudden death.

Protein

A chain of amino acids that occurs in plants and animals. Protein is needed for growth and tissue repair.

Proteinuria (PRO-tee-NUR-ee-uh)

Abnormally high levels of protein in the urine. May be a sign of kidney damage.

Pruritis (prur-EYE-tiss)

Itching. Severe itching can be a symptom of chronic kidney disease.

PTH

Parathyroid hormone. The hormone made by the parathyroid glands that controls the levels of calcium and phosphorus in the body by pulling minerals out of the bones when needed.

Red blood cell

The type of blood cell that carries oxygen. Red blood cells contain hemoglobin, which binds with oxygen to move it throughout the body and give them their color.

Renal (REE-nul)

Related to the kidneys.

Short daily hemodialysis

A type of home dialysis that is done 5-7 days a week for 2-3 hours at a time. Doing the treatments more often feels more like having healthy kidneys. People who use this treatment need fewer medicines and may not have fluid or diet limits. The treatments can be done at any time of day, which may make it easier to keep a job. Most programs require a helper to be on hand during the treatments. The dialysis center provides the machine, training, and 24-hour phone back-up.

Thrill

Vibration caused by blood flow through a fistula or graft. It can be felt by touching the access.

Transplant

An organ from a donor (living or deceased) is surgically placed into the body of a person whose own organ has failed. Having a working transplant feels a lot like having healthy kidneys. Drugs must be taken each day to suppress the immune system and keep it from attacking the foreign organ. These drugs can be costly and may have side effects. For someone who has diabetes and kidney failure, a kidney-pancreas transplant may help both problems at the same time.

Toxin

Chemical waste product or poison.

Ultrasound

A type of imaging that uses high-pitched sound waves to create an image of an internal organ.

Urea (yoo-REE-uh)

A protein waste product containing nitrogen that is made by the liver. Urea is a by-product of metabolism is removed from the body by healthy kidneys.

Urea Reduction Ratio (URR)

A measure of how much urea is removed from the blood by dialysis. It is used to tell if someone is getting enough dialysis.

Uremia (yoo-REE-mee-uh)

A build-up of wastes in the blood due to kidney failure. Symptoms may include fatigue, weakness, lack of energy, poor appetite, weight loss, swelling, metallic or ammonia taste in the mouth, skin color changes, nausea or vomiting, passing out, fuzzy thinking.

Ureter (YUR-eh-tur)

Long thin tubes that carry urine from the kidney to the bladder.

Urethra (yoo-REE-thrah)

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

Urinalysis

Laboratory testing to see what substances are in a urine sample. This can help to diagnose kidney disease.

Urinary (YUR-ih-nehr-ee)

Related to the system that takes wastes from the blood, makes urine, and passes the urine out of the body. The urinary system includes the kidneys, ureters, bladder, and urethra.

Urine

Liquid waste made by the kidneys. Urine contains water, salt, calcium, phosphorus, potassium, urea, and other wastes.

Vascular(VASS-kew-ler) access

A way to reach the bloodstream to do dialysis. For hemodialysis, a strong blood flow is needed. A surgeon will link an artery to a vein under the skin of one arm to make a fistula or a graft. Or, a plastic catheter (tube) will be placed in a central vein in the neck or chest.

Vein

A blood vessel that carries blood back to the heart from other parts of the body.