Assessment of kidney function occurs in different ways, using the presence of symptoms and signs, as well as measurements using urine tests, blood tests, and medical imaging. Wikipedia

Renal functions include maintaining an acid–base balance; regulating fluid balance; regulating sodium, potassium, and other electrolytes; clearing toxins; absorption of glucose, amino acids, and other small molecules; regulation of blood pressure; production of various hormones, such as erythropoietin; and activation of vitamin D. One of the measures of kidney function is the glomerular filtration rate. Wikipedia

Renal function test, based on water filtered out of plasma through glomerular capillary walls into Bowman's capsules Wikidata

Ways of assessing the function of the kidneys Wikidata