Glossary of kidney disease terms

Acute kidney injury (AKI): an abrupt reduction in kidney function with elevation of blood urea nitrogen (BUN) and plasma creatinine

Acute renal failure (ARF): see AKI

Acute tubular necrosis (ATN): most common cause of ARF. It can be caused by ischaemia (blood vessel obstruction) post surgery, sepsis, obstetric complications or severe burns.

Afferent arteriole: transports blood into a structure (e.g. glomerulus)

Anaemia: medical condition in which the percentage of red blood cells circulating in the blood is reduced

Analgesic: a compound that relieves pain

Analgesic nephropathy: kidney disease caused from high consumption of analgesic (pain-relieving) medications

Artery: blood vessel taking blood from the heart to other parts of the body

Azotemia: increased serum urea levels and frequently increased creatinine levels as well

Bacteriuria: the presence of bacteria in the urine

Bladder: a membranous sac

Blood typing: procedure to determine the compatibility between donor and recipient red blood cells

Cadaver: dead person

Calculi: see renal stones

Catheter: hollow tube used to transport fluids to or from the body

Cellulitis: an acute, diffuse, spreading, oedematous, pus-producing inflammation of the deep subcutaneous tissues

cfu: colony forming units

Chronic glomerulonephritis: encompasses several glomerular diseases with a progressive course leading to chronic renal failure

Chronic kidney disease (CKD): at least 3 months of either

  1. structural or functional abnormalities of the kidney that can lead to kidney failure; or
  2. GFR < 60 mL/min/1.73 m2

Chronic renal failure (CRF): slow and progressive deterioration of kidney function -¬now replaced by the phrase chronic kidney disease (see above)

Colic: acute, abdominal pain

Complete proteins: foods, such as meat, fish and eggs, which contain all of the protein-building materials that a body needs

Continuous ambulatory peritoneal dialysis (CAPD): form of continuous peritoneal dialysis in which dialysis fluid is exchanged at regular intervals throughout the day

Continuous cycling peritoneal dialysis (CCPD): form of continuous dialysis in which the peritoneal cavity is continuously filled with dialysis fluid by a machine

Creatinine: a waste product of muscle activity that is removed from the body by the kidneys, and excreted in the urine; high levels of creatinine represent reduced kidney function

Cystitis: inflammation of the bladder

Detrusor muscle: a basket weave of smooth muscle fibres that form the urinary bladder

Diabetes mellitus: disease of the pancreas in which production of insulin is decreased (commonly called diabetes) or insufficient for the body's needs, resulting in disturbed levels of glucose in the blood

Diagnosis: identification of problem from patient's symptoms

Dialyser: the part of a kidney machine which acts like a filter to remove wastes from the body

Dialysis fluid: special fluid used in dialysis into which wastes are passed

Dialysis: a treatment for kidney failure which removes wastes and water from the blood; a process by which small molecules pass from one fluid where they are in high concentration to another fluid where the concentration is lower, through a porous membrane

Diuretic: any agent that enhances the flow of urine

Donor: person who donates something

Dyselectrolytemia:·an imbalance of certain ionized salts (i.e., bicarbonate, calcium, chloride, magnesium, phosphate, potassium, and sodium) in the blood

Efferent arteriole: transports blood out of a structure (e.g. glomerulus)

End-stage kidney disease (ESKD): stage in kidney disease when treatment, such as dialysis or transplantation, becomes necessary. " End-stage" refers to the end of kidney function

End-stage kidney failure (ESKF): irreversible total kidney failure

End-stage renal disease (ESRD): see ESKD

End-stage renal failure (ESRF): See ESKF

Endothelium: tissue that covers body surfaces, lines body cavities and forms glands

Energy foods: foods, particularly sugar and fats, which provide the body with energy Usually measured in calories or kilojoules

Erythropoietin (EPO): a hormone made by the kidneys that stimulates the bone marrow to produce red blood cells

Euglycaemia: a normal level of sugar in the blood

Exchange: one complete cycle of peritoneal dialysis, consisting of inflow, equilibration, and outflow of dialysis fluid

Exoriate: to scratch and remove the skin

External urethral sphincter: striated muscle under voluntary control

Extracorporeal shockwave lithotripsy (ESWL): Ultrasound waves are used to break up stones in the kidney, ureter and bladder into smaller pieces which can eliminated from the body in the urine

Fistula: a passage or duct, commonly used method for providing access to the bloodstream in which a vein and an artery in the arm are joined together

Glomerular capillaries: fist-like structure of 4-8 capillaries subdivided from the afferent arteriole

Glomerular endothelium: composed of cells in continuous contact with the basement membrane

Glomerular filtration membrane: the wall of the glomerular capillary serves as a filtering membrane

Glomerular filtration rate (GFR): the filtration of the plasma per unit time and is directly related to the perfusion pressure in the glomerular capillaries. GFR provides the best estimate of functioning renal tissue. Loss or damage to nephrons lead to a corresponding decrease in GFR.

Glomerulonephritis (GN): condition in which the glomeruli, the tiny filters in the kidneys are damaged; often referred to as nephritis

Glomerulus: a tuft of capillaries that loop into a circular capsule, called the Bowman Capsule

Graft: commonly used method of providing access to the bloodstream in which a vein and an artery in the arm are joined together with a piece of special plastic-like tubing

Haematuria: a large number of red blood cells in the urine

Haemodialysis: treatment for kidney failure in which the blood passes through an artificial dialyser to remove wastes and water

Haemoglobin: colouring matter of the red corpuscles of the blood, that transports oxygen in the blood

Haemorheology: study of the deformation and flow properties of the cellular and plasma components of the blood and the blood vessels

Health: complete physical, mental, emotional and spiritual wellbeing, not merely an absence of disease; a resource for life

Heparin: substance added to blood during haemodialysis to prevent it from clotting in the dialyser during haemodialysis

Hydronephrosis: accumulation of urine in the renal collecting system

Hydroureter: accumulation of urine in the ureter

Hypertension: high blood pressure. May be either the cause of, or the result of, kidney disease

Hypoproteinaemia: abnormal decrease in the amount of protein in the blood

Idiopathic: of unknown origin

Incomplete proteins: foods, such as fruits, vegetables and cereals, which do not contain all of the protein-building materials that a body needs

Insulin: hormone produced by the pancreas that regulates the level of glucose (sugar) in the blood

Intermittent peritoneal dialysis (IPD): form of peritoneal dialysis in which exchanges are done hourly for two or three days each week

Interstitial cystitis: a persistent and chronic form of 'non-bacterial' cystitis occurring primarily in women

Internal urethral sphincter: a ring of smooth muscle at the junction of the urethra and the bladder

Ischaemia: localised anaemia caused by interruption/obstruction of arterial blood flow

Jugular vein: blood vessel located in the side of the neck sometimes used to provide access for haemodialysis

Juxtaglomerular apparatus: composed of 2 types of cells which control renal blood flow, glomerular filtration and renin secretion

Kidney: the primary function of the kidney is to maintain a stable internal environment for optimal cell and tissue metabolism. These tasks are achieved by balancing solute and water transport, excretion of metabolic wastes, conserving nutrients and regulating acids and bases. The kidney also has an endocrine function by secreting the hormones renin, erythropoietin and 1,25-dihydroxyvitamin D3 for the regulation of blood pressure, red blood cell production and calcium metabolism respectively.

Kilojoules: a metric measure of energy value of food (previously called calories)

Kt/V: an expression of the efficiency, or the fractional urea clearance of one haemodialysis session: K is the rate of clearance, t is the amount of time of the session, and V is the urea distribution volume after haemodialysis.

Loop of Henle: a hollow, hairline loop of the nephron, composed of thick and thin portions. Solutes are actively transported across the thick section of the loop resulting in urine concentration.

Membrane: porous material which is used to filter wastes from the blood

Metabolic disturbance: disruption of the chemical processes of the body

Micturition: urination

Neoplasm: any new and abnormal growth, in particular new growth of tissue in which the growth is uncontrolled and progressive

Nephritis: see glomerulonephritis

Nephrolithiasis: see renal stones

Nephrology: the branch of medical science that deals with the kidneys

Nephron: the structural and functional units of the kidney, numbering over a million in each kidney, which are capable of forming urine

Nephropathy: any disease of the kidney

Nephrosis: degeneration of the renal tubular epithelium

Nephrotic syndrome: the excretion of large amounts of protein in the urine per day. This is characteristic of glomerular injury.

Neurogenic bladder: a functional urinary tract obstruction caused by an interruption of the nerve supply to the bladder

Oliguria: diminished excretion of urine (< 400 mL/d or 30 mL/h)

Organ: structurally distinct part of the body which usually performs a particular function. Usually made up of several types of tissue in a very organised structure, e.g. kidney, heart, lungs, liver.

Osteomalacia: inadequate or delayed mineralisation of the bone matrix in mature compact and spongy bone

Peritoneal cavity: abdominal cavity that contains the intestines and other internal organs; lined by the peritoneum or peritoneal membrane

Peritoneal dialysis (PD): treatment for kidney failure in which dialysis fluid is introduced into the peritoneal cavity to remove wastes and water from the blood

Peritoneum: thin membrane that encloses the peritoneal cavity and surrounds the abdominal organs

Peritonitis: inflammation of the peritoneum

Phosphate binder: medication that binds with phosphate in the intestine causing some of the phosphate to be passed in the faeces

Phosphate: mineral in the body fluids regulated by the kidneys. At normal levels, keeps bones and other parts strong and healthy. At high levels, causes itching and painful joints

Plasma creatinine (PCr) concentration: a blood test which is directly related to GFR. When the GFR decreases, PCr increases

Podocytes: specialised cells located in the glomerular epithelium. These foot-like cells interlock and form a network of intracellular clefts called filtration slits which filter the glomerular filtrate, forming the primary urine

Polycystic kidney disease: inherited kidney disease that produces fluid-filled cysts in the kidneys that produce chronic renal failure over many years

Potassium: mineral in the body fluids regulated by the kidneys. At normal levels, helps nerves, muscles and other cells work well. At high levels, may result in cardiac arrest or arrhythmias

Protein: substance obtained from food which builds, repairs and maintains body tissues

Pruritus: itching

Purpura: a disease characterised by purple or livid spots on the skin or mucous membranes caused by blood being forced out of the blood vessels and into the surrounding tissue

Pyuria: white blood cells in the urine

Pyelonephritis: an infection of the renal pelvis and interstitium

Recipient: person who receives (a new organ)

Reflux nephropathy: kidney disease caused by the backflow of urine from the bladder up the ureters into the kidney tissue

Renal arteries: arise as the fifth branches of the abdominal aorta and supply blood to the kidneys

Renal cortex: area of the kidney that contains all the glomeruli and portions of the tubules

Renal failure: loss of kidney function

Renal insufficiency: decline in renal function to about 25% of normal or a GFR of 25-30 ml/min

Renal pelvis: a hollow structure which is an extension of the upper end of the ureter

Renal stones (also known as calculi, nephrolithiasis): masses of crystals and protein and are common causes of urinary tract obstruction in adults

Renin: an enzyme which is produced, secreted, and stored by the kidneys, that plays a role in regulating blood pressure

Renin-angiotensin system: a major hormonal regulator of renal blood flow, which can increase systemic arterial pressure and thus change renal blood flow.

Septicaemia: the presence and persistence of pathogenic microorganisms or their toxins in the blood which affects the body as a whole (i.e. a systemic disease)

Sodium: mineral in the body fluids regulated by the kidneys. Affects the level of water retained in the body tissues

Staghorn calculi: large stones which grow in the pelvis and extend into the calyces to form branching stones

Steroid: medication which reduces inflammation and is used to fight rejection

Subclavian vein: blood vessel located underneath the collarbone sometimes used to provide access for haemodialysis

Tissue typing: procedure to determine the degree of compatibility between lymphocytes (type of white blood cell) of a donor organ and a recipient

Tissue: cells of a particular type massed together, e.g. blood, nerves

Transplant: to transfer, as an organ or a portion of tissue, from one person to another

Ultrafiltration: the process of producing a filtrate of protein-free plasma

Uraemia: a syndrome of renal failure and includes elevated blood urea and creatinine levels accompanied by fatigue, anorexia, nausea and vomiting

Urea: waste product from the breakdown of protein and the major constituent of urine along with water

Ureterorenoscopy (URS): visual inspection of the interior of the ureter and kidney by means of a fiberoptic endoscope

Ureter: tubular structure that transports urine form the kidney to the bladder

Urethra: tubular structure which transports the urine from the bladder to the outside of the body

Urethral syndrome: symptoms of cystitis, such as frequency, urgency and dysuria, but with negative urine cultures

Urinalysis: test to measure the presence of protein, blood and other substances in the urine

Urology: the branch of medicine dealing with the urinary system in females and the genitourinary system in males

Vein: blood vessel returning blood to the heart

Vitamin D: a fat-soluble chemical that is activated naturally in the body on exposure to sunlight