Glossary of kidney terms

Abdomen

The space in the body between the chest and pelvis. Commonly called the belly.
Access (for dialysis)

A way to access the blood for dialysis. This may be by a fistula, graft or catheter. Also known as vascular access.
Acidosis

Too much acid in the body.
Acute

Short-term and happens quickly, usually hours or days.
Acute Kidney Injury (AKI)

Acute kidney injury (AKI) is a sudden and usually temporary drop in kidney function.
Adenine phosphoribosyltransferase deficiency (APRT-D)

Adenine phosphoribosyltransferase deficiency (APRT-D) is a very rare condition that causes crystals and stones to form in the kidneys.
Adequacy

Getting enough dialysis to maintain kidney function. Adequacy is measured by testing how much fluid and waste products are being removed from the blood during each dialysis session.
Adoport

An immunosuppressant medicine (also known as tacrolimus) that prevents the body from rejecting a transplanted organ.
Adrenal gland

A small, triangular-shaped organ above each kidney that makes hormones to help your body handle stress, control blood pressure, and keep salt and water levels balanced.
Albumin

A type of protein. Protein in the urine can be a sign of kidney damage.
Albumin-creatinine ratio (ACR)

The amount of albumin compared to the amount of creatinine in the urine.
Albuminuria

Too much albumin in the urine.
Alport syndrome / Alport's

Alport syndrome is a rare inherited kidney condition that mainly affects the kidneys and hearing.
Altruistic donor

An altruistic donor is a living donor who gives a kidney to someone they have never met.
Amniotic fluid

Fluid that surrounds an unborn baby in the womb during pregnancy.
Amyloidosis

A group of rare conditions caused by a build-up of an abnormal protein called amyloid.
Anaemia

Anaemia is a shortage of red blood cells.
Angioplasty

A procedure to help open up blocked or narrowed blood vessels to improve blood flow.
Angiotensin Converting Enzyme (ACE) inhibitor

Medication to reduce blood pressure. ACE inhibitors can also slow the progression of kidney disease.
Angiotensin Receptor Blocker (ARB)

Medication to reduce blood pressure. ARBs can also slow the progression of kidney disease.
Antibiotics

Medication to treat infections caused by bacteria.
Antibodies

Proteins that are made in the body to destroy bacteria and viruses. They are part of the immune system.
Antigen

A substance that triggers an immune response, important in matching organ donors and recipients.
Anti-neutrophil cytoplasmic antibody (ANCA)

An antibody that is associated with types of vasculitis.
Arteries

Arteries are blood vessels that carry blood from the heart to the rest of the body.
Arteriovenous (AV) fistula

An arteriovenous (AV) fistula is a blood vessel made by a small operation to join an artery and a vein in your arm. This makes one larger, stronger blood vessel that can be used to access your blood for dialysis. Also known as a fistula.
Atypical Haemolytic Uraemic Syndrome (aHUS)

Atypical Haemolytic Uraemic Syndrome (aHUS) is an extremely rare kidney condition that occurs due to a fault in the complement system, which is part of the body’s immune system and helps it to fight infections.
Automated peritoneal dialysis (APD)

A form of peritoneal dialysis where a machine does your dialysis exchanges overnight while you sleep.
Autosomal dominant polycystic kidney disease (ADPKD)

Autosomal dominant polycystic kidney disease (ADPKD) is a rare inherited condition that causes cysts to develop in the kidneys and liver.
Autosomal dominant tubulointerstitial kidney disease (ADTKD)

Autosomal dominant tubulointerstitial kidney disease (ADTKD) is a rare inherited condition that causes damage to the tiny tubules of the kidneys.
Autosomal recessive polycystic kidney disease (ARPKD)

Autosomal recessive polycystic kidney disease (ARPKD) is a rare inherited condition that causes cysts to develop in the kidneys and liver.
Azathioprine

An immunosuppressant medicine that prevents the body from rejecting a transplanted organ.
Bacteria

A type of germ. Bacteria are microscopically tiny, single-celled organisms. Most are harmless, but some cause disease.
Bartter syndrome / Bartters

Bartter syndrome is a very rare inherited kidney condition that causes excess salt and water to be lost from the body in the urine.
Beta blockers

Medication that helps to control the heart’s rhythm and reduce high blood pressure.
Bicarbonate

A chemical that helps keep your body’s acid levels in balance.
Biopsy

A small procedure where a needle is used to take a tiny piece (around half the size of a matchstick) of one of your kidneys to check their function and structure.
BK nephropathy

BK nephropathy is a rare condition that can occur after a kidney transplant. It is caused by the activation of the BK virus.
BK virus

A usually harmless virus that can become active and cause problems in people with weakened immune systems, such as after transplantation.
Bladder

The organ in your body that holds urine (wee).
Blood cells

The microscopically tiny units that form the solid part of the blood. There are three main types: red blood cells, white blood cells and platelets.
Blood group

An inherited classification of red blood cells.
Blood pressure (BP)

Blood pressure (BP) is the force of blood on the inside walls of blood vessels.
Blood vessels

The tubes that carry blood around the body. The main blood vessels are the arteries and veins.
C3 glomerulopathy (C3G)

C3 glomerulopathy (C3G) is a rare immune system disorder that causes damage to the tiny filters in the kidney (glomeruli).
Calcimimetic

A medication that copies the effects of calcium in the body.
Calciphylaxis

Calciphylaxis is a rare condition where calcium builds up in small blood vessels that can cause painful skin wounds. It can develop in people who have had dialysis for a long time.
Calcium

A mineral that strengthens the bones.
Cardiologist

A specialist heart doctor.
Catheter

A flexible plastic tube used to enter the body. Different types of catheter may be used for dialysis or to drain urine from the bladder.
Cells

The tiny units that every living thing is made from.
Cholesterol

A fatty substance in the blood that your body needs. Too much cholesterol can cause health problems.
Chronic

Present for a long time and slow to change, usually over months or years.
Chronic kidney disease (CKD)

Chronic kidney disease (CKD) is a long-term condition where the kidneys do not work as well as they should. Waste products start to build up in your body as your kidneys can’t remove them properly. Damage to your kidneys’ filter system lets blood and protein leak into your urine.

‘Chronic’ means that it is a long-term condition. It does not mean that the condition is severe. Most people with CKD have very mild symptoms and are managed by their GP. Only one in 50 people with CKD will develop kidney failure and need to receive dialysis treatment or have a kidney transplant.

CKD can affect people of all ages but older adults aged over 60 are more likely to develop CKD. CKD can run in families and is more common in people from Asian and Black backgrounds.

Some people are at increased risk of developing CKD because they have other conditions such as diabetes, high blood pressure (hypertension) or heart disease.
Clearance

The removal of the toxic waste products of food from the body.
Collagen fibers

Strong proteins found in bones and connective tissue.
Complement system

Part of the body’s immune system that is involved in some kidney diseases.
Computerised tomography (CT) scan

A test that uses a series of low-intensity X-rays to build up a picture of an organ in the body.
Conservative care

Conservative care is treatment for people with advanced kidney failure who decide not to have dialysis or a transplant. Also known as supportive care or conservative kidney management.
Conservative kidney management

Treatment for people with advanced kidney failure who decide not to have dialysis or a transplant. Also known as supportive care or conservative care.
Continuous ambulatory peritoneal dialysis (CAPD)

A form of peritoneal dialysis where you do your exchanges in the daytime.
Contrast

A special dye used in imaging tests that can sometimes harm the kidneys.
C-reactive Protein (CRP)

A blood test that shows inflammation that can be higher in infections.
Creatinine

A waste substance produced by the muscles. The higher the blood creatinine level, the worse the kidneys are working. The blood creatinine level is used to calculate the eGFR, an estimate of kidney function.
Cross-match

A test to check compatibility between donor and recipient before transplant.
Cystinosis

Cystinosis is a rare inherited condition where a substance called cystine builds up in cells causing damage to the kidneys and eyes.
Cystinuria

Cystinuria is a rare inherited kidney condition where too much of a substance called cystine builds up in the urine and forms kidney stones.
Cysts

Fluid-filled sacs that can vary in size and may occur anywhere in the body. Large cysts can affect how an organ works.
Deceased donor transplant

Receiving a kidney from someone who has died.
Dehydration

When the body does not contain enough water to function properly.
Dense deposit disease (DDD)

Dense deposit disease (DDD) is a rare immune system disorder that causes damage to the tiny filters in the kidney (glomeruli).
Dent disease

Dent disease is a very rare kidney condition that is caused by an excess of calcium and proteins in the urine and can lead to kidney stones.
Diabetes

Diabetes is a condition that causes an increase in blood sugar levels.
Diabetic nephropathy

Kidney damage caused by long-term diabetes. This is one of the leading causes of chronic kidney disease.
Dialysis

A treatment for kidney failure that uses a machine or equipment to clean your blood. There are two different kinds of dialysis: haemodialysis (HD) and peritoneal dialysis (PD).
Dialysis fluid

The liquid that helps to clean your blood during dialysis.
Diastolic blood pressure

A blood pressure reading taken when the heart is relaxed. It is taken after the systolic blood pressure and is the second figure in a blood pressure measurement.
Diuretics

Medication to help you pass more urine, also known as water tablets.
Donation after Brain Death (DBD)

Organ donation from a person whose brain has stopped working but whose heart is still beating.
Donation after Circulatory Death (DCD)

Organ donation after the heart has stopped beating and circulation has stopped.
Donor

A person who donates (gives) an organ to another person (the recipient).
Dry weight

The ideal weight of a dialysis patient after excess fluid has been removed from the body.