Diagnosing kidney disease begins with sophisticated testing
To pinpoint your diagnosis, check for kidney damage and evaluate how well your kidneys are working, nephrologists use several sophisticated tests.
Blood pressure screening for kidney disease diagnosis
To determine diastolic (the bottom number, which is also the lower of the two numbers, measures the pressure in the arteries between heartbeats (when the heart muscle is resting between beats and refilling with blood) and systolic (the top number, which is also the higher of the two numbers, measures the pressure in the arteries when the heart beats—when the heart muscle contracts).
Blood tests for diagnosing kidney disease
Following are a variety of blood tests that help determine whether or not you have kidney disease:
- CBC – complete blood count of your red blood cells, white blood cells, and platelets—low CBC level can mean kidney function is reduced.
- Creatinine – waste product of muscles that is normally eliminated by the kidneys, may be elevated when kidney function is reduced.
- Creatinine clearance – measure of how well creatinine is removed by the kidneys over a 24-hour period of urine collection. When kidney function is reduced, clearance may be low.
- Blood electrolyte tests – also known as chemistries. Electrolytes are filtered out of the blood by the kidneys. Abnormal levels may indicate reduced kidney function.
- Hemoglobin A1C – measures how well blood sugar (called glucose) is controlled during three months before testing. Elevation indicates blood sugar is not well-controlled and may be causing reduced kidney function.
- Blood urea nitrogen (BUN) – also a waste product that is eliminated by the kidneys. BUN is elevated when kidney function is reduced.
- Glomerular filtration rate (GFR) – the best measure of kidney function and also determines the stage or progression of the disease. The higher the numbers of the GFR, the better the kidneys are working.
Urine testing for excess protein
Excess protein may signal a problem. These urine tests help diagnose kidney disease:
- Urine dipstick – a sample of your urine is tested for excess protein or proteinuria. Protein in the urine can be a sign that something is wrong with the kidneys’ ability to filter the blood properly.
- Urine culture – to check for white blood cells, and bacteria.
- Urine output measurements – the amount of urine you excrete in a day may help your doctor determine the cause of your kidney failure.
Imaging studies to assess kidney size and look for abnormalities
Scans such as these may be used to measure the size of your kidneys and look for structural abnormalities and blockages, such as kidney stones or tumors:
- Ultrasound exam
- Computerized tomography (CT) scan
- Magnetic resonance imaging (MRI) scan
- Voiding cystourethrogram (VCUG)
- Dimercaptosuccinic acid scintigraphy (DMSA)
Kidney biopsy to check for damage and disease
A biopsy is a test involves removing a small sample of kidney tissue small through a thin needle to check for damage and signs of certain diseases. The tissue is examined under a microscope to determine the exact cause of the kidney disease, and the biopsy findings may also help us determine the best treatment for your kidney disease.
Peritoneal equilibrium test (PET) assesses kidney ability to clear waste
A PET scan takes samples of blood and used dialysis solution and analyzes to determine how quickly wastes and fluid are being cleared from your blood during peritoneal dialysis.
Digital rectal examination (DRE) if kidney infection is suspected
The DRE is a physical exam of the prostrate if a kidney infection is suspected and to determine if a swollen prostrate is blocking the neck of the bladder.