Chronic kidney disease

Chronic kidney disease (CKD) is a type of long-term kidney disease, defined by the sustained presence of abnormal kidney function and/or abnormal kidney structure. To meet criteria for CKD, the abnormalities must be present for at least three months. Early in the course of CKD, patients are usually asymptomatic, but later symptoms may include leg swelling, feeling tired, vomiting, loss of appetite, and confusion. 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. Additionally CKD patients have markedly increased cardiovascular complications with increased risks of death and hospitalization. CKD can lead to end-stage kidney failure requiring kidney dialysis or kidney transplantation.

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

Testing people with risk factors (case-finding) is recommended. Initial treatments may include medications to lower blood pressure, blood sugar, and cholesterol. 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. Loop diuretics may be used to control edema and, if needed, to further lower blood pressure. NSAIDs should be avoided. Other recommended measures include staying active, and "to adopt healthy and diverse diets with a higher consumption of plant-based foods compared to animal-based foods and a lower consumption of ultraprocessed foods." Plant-based diets are feasible and are associated with improved intermediate outcomes and biomarkers. An example of a general, healthy diet, suitable for people with CKD who do not require restrictions, is the Canada Food Guide Diet. People with CKD who require dietary restrictions or who have other specific nutritional problems should be referred to a dietitian. Treatments for anemia and bone disease may also be required. Severe disease requires hemodialysis, peritoneal dialysis, or a kidney transplant for survival.

Chronic kidney disease affected 753 million people globally in 2016 (417 million females and 336 million males.) In 2015, it caused 1.2 million deaths, up from 409,000 in 1990. 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.