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Tests

The goals of testing for proteinuria include screening those at risk, detecting the condition, determining its underlying cause, evaluating the type and quantity of protein being released, and evaluating kidney function. When proteinuria is detected, patients are monitored at intervals to see if it resolves or becomes worse. Both urine and blood tests may be ordered to evaluate proteinuria.

Laboratory tests

Several tests may be ordered on either 24-hour or random urine samples:

  • Urinalysis – evaluation of a urine sample by visual inspection, chemical testing and, in some cases, microscopic analysis.
  • Protein urine, 24-hour urine – measures the amount of protein excreted in the urine in a 24-hour period; this is a more accurate assessment of the degree of proteinuria than a random urine.
  • Albumin/creatinine ratio (UACR), random urine - measures albumin in a random sample and corrects it for the amount of creatinine (a substance released by the body at a steady rate); alternative to 24-hour sample.
  • Protein/creatinine ratio (UPCR), random urine - measures protein in a random sample and corrects it for the amount of creatinine; alternative to 24-hour sample.

A few tests may be run on both urine and blood:

  • Creatinine urine - uses a 24-hour urine sample and a blood sample to evaluate kidney function based on the rate of creatinine excretion from the body.
  • Protein electrophoresis - a test used to determine the different types and relative concentrations of protein present in the urine; may also be performed to evaluate protein in the blood.

These tests may also be ordered and are run primarily on blood only:

  • eGFR (estimated glomerular filtration rate) - uses a blood creatinine level to calculate the estimated rate of urine filtration; rate decreases with progressive kidney damage.
  • Urea - a blood test used to evaluate kidney function.
  • Creatinine - a blood test used to evaluate kidney function; less frequently, it may be done on urine. (Note: Although creatinine may be measured in urine samples, it is usually measured to be included as part of a ratio or calculation.)
  • Total protein - a blood test that measures all of the protein in the serum.
  • Albumin - a blood test that measures the concentration of albumin in blood.

A kidney biopsy may also be ordered. This is a procedure that is sometimes performed to look at a small sample of kidney tissue under the microscope for evidence of kidney disease or damage.

Non-laboratory tests

  • Imaging scans of the kidney to detect the presence and determine the severity of kidney disease or damage.
  • Blood pressure; may be measured as part of investigation of cause of proteinuria; frequently monitored in those who have hypertension or are at risk of developing it.

Last Review Date: June 7, 2017