Last reviewed by Dr. Leena Joshi, MD, July 2026
Kidney lab results explained include blood and urine tests that measure how well the kidneys filter waste and maintain fluid balance. Dr. Joshi reviews kidney function labs including creatinine, glomerular filtration rate (GFR), blood urea nitrogen (BUN), and urinalysis to assess kidney health in San Mateo County patients. Dr. Joshi interprets these results in the context of each patient’s medical history and may recommend lifestyle changes, medication adjustments, or additional testing based on findings.
What is kidney function testing?
Kidney function labs are blood and urine tests that show how well the kidneys are working. The kidneys filter waste products from the blood, balance fluids, and help control blood pressure. When kidney function declines, waste can build up in the body. Common kidney lab results explained by Dr. Joshi include serum creatinine, which measures a waste product from muscles, and estimated glomerular filtration rate (GFR), which shows the filtering capacity of the kidneys. Blood urea nitrogen (BUN) measures another waste product. Urinalysis checks for protein, blood, or other substances in urine that may signal kidney problems. Dr. Joshi uses these tests to detect kidney disease early, monitor existing conditions, and adjust treatment plans for patients throughout San Mateo County. Understanding kidney lab results explained helps patients take an active role in protecting their kidney health.
Signs and symptoms
Patients may need kidney function testing if they experience:
- Swelling in the legs, ankles, feet, or face
- Changes in urination frequency, color, or amount
- Persistent fatigue or weakness
- High blood pressure that is difficult to control
- Foamy or bubbly urine
- Nausea, loss of appetite, or metallic taste
- Shortness of breath or difficulty concentrating
How Dr. Joshi manages kidney function monitoring
Dr. Joshi begins by reviewing the patient’s complete medical history, current medications, and risk factors such as diabetes or high blood pressure. Dr. Joshi orders appropriate kidney lab tests and explains what each result means in plain language. When kidney lab results explained show abnormalities, Dr. Joshi determines whether the changes are acute or chronic and identifies potential causes. Dr. Joshi may recommend repeat testing to confirm findings or track trends over time. For patients with reduced kidney function, Dr. Joshi develops individualized management plans that may include dietary modifications, blood pressure control, medication adjustments, or treatment of underlying conditions. Dr. Joshi coordinates care with primary care physicians and other specialists when needed. Throughout San Mateo County, Dr. Joshi emphasizes patient education so individuals understand their kidney lab results explained and can make informed decisions about their health. Regular monitoring allows Dr. Joshi to detect changes early and intervene before kidney function declines further.
When to see a nephrologist for kidney lab results
Dr. Joshi recommends nephrology consultation when patients have:
- GFR below 60 for three months or longer
- Persistent protein in the urine
- Rapidly declining kidney function
- Kidney disease with diabetes or high blood pressure
- Abnormal kidney lab results that need specialist interpretation
- Family history of kidney disease with concerning test results
Frequently asked questions
What is a normal GFR?
A normal GFR is typically 90 or above, though it naturally declines with age. Dr. Joshi considers GFR along with other factors to assess kidney health. A GFR below 60 for three months may indicate chronic kidney disease.
What does high creatinine mean?
Elevated creatinine may indicate reduced kidney function, as the kidneys are not filtering this waste product effectively. Dr. Joshi evaluates creatinine levels alongside GFR and other tests to determine the cause and appropriate management.
How often should kidney labs be checked?
Testing frequency depends on individual risk factors and existing kidney conditions. Dr. Joshi may recommend annual testing for at-risk patients or more frequent monitoring for those with known kidney disease.
Can kidney lab results improve?
Some kidney function changes can improve with treatment of underlying causes such as dehydration or medication effects. Dr. Joshi works with patients to optimize factors that support kidney health and may see stabilization or improvement in some cases.
What is the BUN to creatinine ratio?
This ratio compares two waste products and can help Dr. Joshi identify whether kidney problems are related to dehydration, bleeding, or other conditions. The ratio provides additional context beyond individual test results.
Should I fast before kidney function tests?
Most basic kidney labs do not require fasting, though Dr. Joshi may request fasting if other tests are being done simultaneously. Dr. Joshi provides specific instructions before each lab appointment.
Dr. Joshi sees patients at two convenient San Mateo County locations: 1750 El Camino Real, Suite 301, Burlingame, and 1800 Sullivan Avenue, Suite 507, Daly City. To schedule a consultation regarding kidney lab results explained or kidney health concerns, call (650) 355-5551.
This page is for general education and is not a substitute for medical advice. Always consult your physician about your specific situation.
Medically reviewed by Leena Joshi, MD.