Chronic kidney disease

Chronic kidney disease
Other names	Chronic renal disease, kidney failure, impaired kidney function[1]
Illustration of a kidney from a person with chronic renal failure
Specialty	Nephrology
Symptoms	Early: None[2] Later: Leg swelling, feeling tired, vomiting, loss of appetite, confusion[2]
Complications	Heart disease, high blood pressure, anemia[3][4]
Duration	Long-term[5]
Causes	Diabetes, high blood pressure, glomerulonephritis, polycystic kidney disease[5][6]
Risk factors	Genetic predisposition, low socioeconomic status[7]
Diagnostic method	Blood tests, urine tests[8]
Treatment	Medications to manage blood pressure, blood sugar, and lower cholesterol, renal replacement therapy, kidney transplant[9][10]
Frequency	753 million (2016)[1]
Deaths	1.2 million (2015)[6]

Chronic kidney disease (CKD) is a type of long-term kidney disease, in which either there is a gradual loss of kidney function which occurs over a period of months to years, or an abnormal kidney structure (with normal function).^[2][5] Initially generally no symptoms are seen, but later symptoms may include leg swelling, feeling tired, vomiting, loss of appetite, and confusion.^[2] Complications can relate to hormonal dysfunction of the kidneys and include (in chronological order) high blood pressure (often related to activation of the renin–angiotensin system), bone disease, and anemia.^[3][4][11] Additionally CKD patients have markedly increased cardiovascular complications with increased risks of death and hospitalization.^[12] CKD can lead to kidney failure requiring kidney dialysis or kidney transplantation.^[9]

Causes of chronic kidney disease include diabetes, high blood pressure, glomerulonephritis, and polycystic kidney disease.^[5][6] Risk factors include a family history of chronic kidney disease.^[2] Diagnosis is by blood tests to measure the estimated glomerular filtration rate (eGFR), and a urine test to measure albumin.^[8] Ultrasound or kidney biopsy may be performed to determine the underlying cause.^[5] Several severity-based staging systems are in use.^[13][14]

Screening at-risk people is recommended.^[8] Initial treatments may include medications to lower blood pressure, blood sugar, and cholesterol.^[10] Angiotensin converting enzyme inhibitors (ACEIs) or angiotensin II receptor antagonists (ARBs) are generally first-line agents for blood pressure control, as they slow progression of the kidney disease and the risk of heart disease.^[15] Loop diuretics may be used to control edema and, if needed, to further lower blood pressure.^[16][10][17] NSAIDs should be avoided.^[10] Other recommended measures include staying active, and certain dietary changes such as a low-salt diet and the right amount of protein.^{[vague][10][18]} Treatments for anemia and bone disease may also be required.^[19][20] Severe disease requires hemodialysis, peritoneal dialysis, or a kidney transplant for survival.^[9]

Chronic kidney disease affected 753 million people globally in 2016 (417 million females and 336 million males.)^[1][21] In 2015, it caused 1.2 million deaths, up from 409,000 in 1990.^[6][22] The causes that contribute to the greatest number of deaths are high blood pressure at 550,000, followed by diabetes at 418,000, and glomerulonephritis at 238,000.^[6]