CNN key terms

The microscopic functional unit of the kidney, made of a glomerulus and its tubule. Each kidney holds about a million nephrons, which filter blood and adjust water, electrolyte, and acid levels.

The volume of plasma the glomeruli filter each minute, usually reported in milliliters per minute. It is the best single measure of kidney function and falls as kidney disease advances.

A hormone cascade triggered when the kidney releases renin in response to low blood pressure or low sodium. It narrows blood vessels and makes the kidney retain sodium and water, raising blood pressure.

A hormone made mainly by the kidney that signals bone marrow to produce red blood cells. Production falls in chronic kidney disease, which leads to anemia and fatigue.

A state in which the blood is too acidic because the kidneys cannot excrete enough hydrogen ions or reclaim enough bicarbonate. It is common in advanced kidney disease and contributes to bone loss and muscle wasting.

Kidney damage or reduced function present for at least three months, staged 1 through 5 by GFR. Stage 5 means the kidneys are near or at failure and kidney replacement therapy may be needed.

A sudden decline in kidney function over hours to days, shown by a rising creatinine or falling urine output. Causes are grouped as prerenal, intrinsic kidney damage, and postrenal obstruction.

Inflammation of the glomeruli, often caused by immune attack, that produces blood and protein in the urine and reduces filtration. It may resolve, recur, or progress to chronic kidney disease.

A pattern of heavy protein in the urine, low blood albumin, body swelling, and high cholesterol caused by glomerular damage. It raises risk of infection and blood clots.

A blood potassium level above the normal range, dangerous because it can trigger fatal heart rhythms. In kidney disease it results from poor excretion and is worsened by certain medicines and high-potassium foods.

The accumulation of waste products in the blood when the kidneys fail, causing fatigue, nausea, itching, confusion, and eventually coma. Dialysis or transplantation clears these wastes.

A waste product of muscle activity that healthy kidneys filter out, so higher levels suggest reduced filtration. It is used with age and sex to estimate GFR and to calculate dialysis dose.

A blood test for nitrogen from urea, a waste made when protein is broken down and normally cleared by the kidney. Levels rise with kidney impairment but also shift with hydration, diet, and bleeding.

A number calculated from serum creatinine plus age, sex, and sometimes cystatin C to approximate kidney function without a timed urine collection. It guides staging and referral decisions.

Excess protein in the urine, a marker of glomerular injury and a strong predictor of kidney disease progression and heart risk. It is detected by dipstick or quantified with an albumin-to-creatinine ratio.

A painless imaging test using sound waves to show kidney size, shape, cysts, stones, and urinary blockage. It helps separate long-standing scarring from reversible causes such as obstruction.

Removal of a small sample of kidney tissue with a needle so it can be examined under a microscope. It identifies the cause of glomerular disease and guides therapy but carries a bleeding risk.

A therapy that pumps blood through an artificial filter outside the body to remove wastes and extra fluid and to correct electrolytes. It needs a vascular access and is usually done several times each week.

A home therapy that uses the lining of the abdomen as a filter. Dialysate enters through a catheter, sits for a dwell period, then drains, carrying wastes and water out of the body.

A surgically connected artery and vein, usually in the arm, that enlarges to carry high blood flow for hemodialysis. It is preferred because it lasts longer and infects less often than other accesses.

A tube placed in a large vein to allow immediate dialysis when no fistula or graft is ready. It carries higher risks of infection, clotting, and vein narrowing, so it is meant for short-term use.

Removal of extra water from plasma across a semipermeable membrane, driven by a pressure difference. During dialysis it controls the patient's volume, and the rate is set from the fluid gained since the last treatment.

The body weight at which a dialysis patient has no excess fluid yet stays normotensive and free of cramping or breathlessness. It is reassessed regularly and sets how much fluid each treatment removes.

A formula used to measure how much dialysis a patient receives, in which K is clearance, t is treatment time, and V is the urea distribution volume. Higher values mean more urea was removed.

A complication of overly rapid dialysis in which fluid shifts into the brain cause headache, nausea, confusion, or seizures. It is prevented by starting dialysis gently and limiting the first urea drop.

Infection of the peritoneal cavity, most often from touch contamination during a dialysis exchange. Cloudy drained fluid and belly pain are hallmarks, and prompt antibiotics plus catheter care are required.

Surgery that places a donor kidney, usually in the pelvis, to restore kidney function. It offers the longest survival and best quality of life of any replacement therapy but requires lifelong immunosuppression.

An immune attack on a transplanted kidney that can appear days to months after surgery, with rising creatinine, fever, and less urine. It is treated by intensifying immunosuppressive therapy.

Medicines that dampen the immune response so the body will not reject a transplanted kidney. They must be taken exactly as prescribed and raise the risk of infection and some cancers.

An eating plan that limits sodium, potassium, phosphorus, and sometimes protein and fluid to match what the failing kidneys can handle. It is individualized and revised as kidney function changes.

A daily limit on all liquids, including soup, ice, and gelatin, set for people whose kidneys cannot remove enough water. It prevents swelling, breathlessness, and rapid weight gain between treatments.

Medicines taken with meals to trap phosphorus in food so it passes in stool instead of being absorbed. They help prevent itching and blood vessel calcification caused by high phosphate levels.

Daily habits patients use to protect a dialysis access, such as checking the thrill, keeping the site clean, avoiding pressure or tight sleeves, and rotating needle sites. Good care prevents clotting and infection.

Teaching and coaching that helps people with kidney disease track symptoms, follow their plan, solve problems, and make choices. It builds confidence and is linked to better adherence and outcomes.

Infection control steps applied to every patient, including hand hygiene, gloves, and eye protection when splashes are possible. In dialysis units they extend to careful catheter and needle-site handling.

A team-based cycle of measuring performance, finding why problems occur, testing a change, and measuring again. Dialysis facilities use it to improve adequacy, anemia management, and infection rates.

Federal rules a dialysis facility must satisfy to be paid by Medicare, covering staffing, water quality, infection control, and patient care. Surveyors inspect facilities to confirm compliance.

Handing a nursing task to a trained unlicensed worker while the nurse keeps accountability for the result. The nurse must check state rules, facility policy, and the worker's competence first.