Renal Function Tests (RFTs)—often called a kidney panel or kidney function blood tests—are a group of laboratory tests that help evaluate how well your kidneys are working. Your kidneys filter waste products and extra fluid from the blood, help balance electrolytes (salts and minerals), and play a key role in blood pressure control and bone health.

An RFT panel commonly includes:

• Creatinine: A waste product from normal muscle activity. Healthy kidneys remove creatinine from the blood. If kidney filtering slows down, creatinine levels can rise.

• Estimated glomerular filtration rate (eGFR): A calculated value based on creatinine (and often age and sex) that estimates how efficiently your kidneys filter blood. Lower eGFR generally means reduced kidney filtration. eGFR is one of the most useful single numbers for assessing kidney function over time.

• Blood urea nitrogen (BUN) / Urea: Another waste product formed when the body breaks down protein. Higher BUN/urea can suggest reduced kidney function, but it can also rise with dehydration, high-protein diets, bleeding in the stomach/intestines, or certain medications.

• Electrolytes (often sodium, potassium, chloride, bicarbonate/CO2): These reflect fluid balance and acid–base status. Kidney problems can cause abnormal potassium (too high or too low), changes in bicarbonate (metabolic acidosis), and other electrolyte imbalances that may affect the heart, muscles, and nerves.

• Sometimes included: calcium, phosphate, uric acid, and albumin depending on the lab and clinical question.

What results may mean in plain language: Normal results generally suggest your kidneys are filtering waste and balancing electrolytes appropriately. Abnormal results do not always mean chronic kidney disease—temporary issues like dehydration, recent intense exercise, infection, or medication effects can shift values. Doctors interpret RFTs alongside your symptoms, medical history, blood pressure, urine tests (such as urine albumin-to-creatinine ratio), and repeat measurements over time.

Your clinician may order Renal Function Tests to screen for kidney problems, investigate symptoms, monitor an existing condition, or ensure treatments are safe for your kidneys. RFTs are commonly used as a baseline “kidney function” check before starting or adjusting medications and before certain imaging studies that use contrast dye.

Symptoms that may prompt testing include:

• Swelling in the legs, ankles, face, or around the eyes (fluid retention)

• Changes in urination (less urine, foamy urine, blood in urine, frequent nighttime urination)

• Fatigue, weakness, nausea, poor appetite, or confusion

• Shortness of breath (fluid overload) or high blood pressure

• Muscle cramps, palpitations, or tingling (possible electrolyte imbalance)

Common reasons to check a kidney panel include:

• Diabetes or high blood pressure (leading causes of chronic kidney disease)

• Family history of kidney disease or known structural kidney problems (e.g., polycystic kidney disease)

• Older age, obesity, cardiovascular disease, or smoking (higher kidney risk)

• Recurrent urinary tract infections, kidney stones, or urinary obstruction symptoms

• Monitoring during illness that can affect kidneys (dehydration, severe infection/sepsis, shock)

• Medication monitoring—especially drugs that can impact kidneys or electrolytes (e.g., NSAIDs like ibuprofen/naproxen, ACE inhibitors/ARBs, diuretics, lithium, some antibiotics, chemotherapy)

• Before and after procedures with iodinated contrast, or when adjusting drug dosing (many medications require dose changes when eGFR is low)

• Chronic kidney disease (CKD)
• Acute kidney injury (AKI)
• Diabetic kidney disease (diabetic nephropathy)
• Hypertensive nephrosclerosis (kidney damage from long-standing high blood pressure)
• Glomerulonephritis and nephrotic/nephritic syndromes
• Polycystic kidney disease (PKD)
• Urinary tract obstruction (e.g., enlarged prostate/BPH, kidney stones)
• Urinary tract infection (UTI) and pyelonephritis (kidney infection)
• Electrolyte disorders (especially hyperkalemia, hyponatremia, metabolic acidosis)
• Dehydration or volume depletion affecting kidney filtration

• Screening and early detection of kidney disease, especially in people with diabetes or high blood pressure
• Monitoring kidney function over time (eGFR/creatinine trends) to guide lifestyle and treatment decisions
• Medication safety and dose optimization (ensuring drugs are appropriate for your kidney function)
• Electrolyte and fluid balance monitoring to support heart rhythm and muscle function
• Pre-operative or pre-procedure assessment (including before contrast imaging) to reduce kidney-related risks
• General wellness checkups for people with risk factors (family history, older age, cardiovascular disease)
• Managing complications of kidney disease such as acid–base imbalance and mineral balance issues