Diagnosing CKD

PART 1

GFR and the Stages of Chronic Kidney Disease

Glomerular Filtration Rate (GFR)
Glomerular filtration rate (GFR) is the standard means of expressing overall kidney function. Normal GFR is approximate; it is about 100-140 mL/min in men and 85-115 mL/min in women.

Patients are divided into five stages of chronic kidney disease based on their GFR. In the first four stages the kidneys are still working, but function lessens with each successive stage. In stage 5, kidney failure, the kidneys stop functioning altogether. READ MORE

PART 2

Testing for CKD

Because CKD can progress for years with few or no symptoms until it reaches an advanced stage, anyone with risk factors for the disease should be routinely tested.

There are three main types of tests for CKD: urine, blood, and imaging tests.

PART 3

Urine Tests

Urinalysis
In urinalysis, the urine is examined for the presence of substances that normally shouldn’t be there.

• Dipstick tests check for albumin (protein), normally found in only minute quantities, and other substances. The presence of albumin indicates kidney damage.


• Microscopic examinations look for the presence of various substances, including red and white blood cells and crystals (solids).


• 24-hour urine tests examine urine that has been collected over a period of 24 hours. They look for albumin, urea nitrogen, and creatinine.

URINE TEST WHAT IT DOES Urine albumin Looks for protein Urine white and red blood cell count Checks for presence of white or red blood cells in urine Urine sodium and creatinine levels Tests to see if kidney problems are acute or chronic

PART 4

Blood Tests

BLOOD TEST WHAT IT DOES Creatinine and urea nitrogen (BUN) Looks for creatinine and urea nitrogen (waste products) Estimated glomerular filtration rate (eGFR) Calculates how well kidney is filtering from amount of waste products in blood Electrolyte levels Checks for electrolyte imbalances Blood cell count Checks for anemia caused by low red blood cell production pH balance Tests acid-alkaline balance of blood

PART 5

Other Tests: Ultrasound and Biopsy

• Ultrasound exams can be done to assess the size of the kidney, check for the presence of obstructions, and determine blood flow into the kidney. In most types of kidney disease, the kidneys shrink in size because of the loss of healthy tissue. Ultrasound exams may reveal the presence of kidney stones or show blockage of the arteries that feed into the kidneys.


• Biopsy of kidney tissue may be done if the cause of kidney disease can’t be otherwise determined.