Ulta Lab Tests

Renal Function

Renal function tests show how well your kidneys filter waste, balance fluids and minerals, and help control blood pressure and bone health. Because early kidney problems are often silent, routine blood and urine testing can find issues before symptoms start—especially if you have diabetes, high blood pressure, heart disease, a family history of kidney failure, or a history of urinary problems or stones.

A proactive plan begins with a renal function (kidney) panel—creatinine with estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN), electrolytes (sodium, potassium, chloride), and bicarbonate/CO2—and often includes calcium and phosphorus. Add cystatin C to refine eGFR, and pair blood tests with urine albumin-to-creatinine ratio (ACR) and urinalysis to check for kidney damage. These labs support screening, diagnosis, staging, and monitoring, but they do not replace a clinician’s evaluation or imaging when needed.

Signs, Symptoms & Related Situations

  • Often silent early: abnormal labs on a routine check

  • Urinary clues: foamy urine (protein), blood in urine, frequent nighttime urination, burning/urgency (UTI signs)

  • Whole-body: ankle/leg swelling, fatigue, poor appetite, nausea, itchy skin, high blood pressure

  • Risk contexts: diabetes, hypertension, cardiovascular disease, obesity, kidney stones, recurrent UTIs, autoimmune disease, long-term NSAID use, family history of kidney failure

  • Seek urgent care now: chest pain, severe shortness of breath, confusion, little or no urine, severe flank pain, or rapidly worsening swelling

All symptoms and risks should be reviewed by a qualified clinician.

Why These Tests Matter

What testing can do

  • Detect kidney problems early and stage chronic kidney disease (CKD) using eGFR and ACR

  • Differentiate causes (e.g., dehydration/acute kidney injury vs. chronic disease) by combining renal panel results with urinalysis and targeted add-ons

  • Monitor complications such as electrolyte shifts, metabolic acidosis (low bicarbonate), and bone-mineralimbalances (calcium/phosphorus)

What testing cannot do

  • Identify the exact cause in every case—some situations need imaging, serologies, or biopsy

  • Replace blood-pressure/diabetes management or medication review

  • Provide treatment or dosing advice—use results to plan with your clinician

What These Tests Measure (at a glance)

  • Creatinine & eGFR: core measure of filtration. eGFR <60 for ≥3 months suggests CKD; trends matter more than one value.

  • Cystatin C (± eGFRcys): confirms/refines eGFR when creatinine is borderline or muscle mass is unusual.

  • BUN: waste product that rises with reduced kidney function or dehydration—interpret with creatinine and history.

  • Electrolytes:

    • Sodium (Na?): fluid balance; abnormal values can reflect hydration or hormonal issues.

    • Potassium (K?): high levels can be dangerous in kidney disease; low levels may occur with losses or certain medicines.

    • Chloride (Cl?) & Bicarbonate/CO2: help assess acid–base status; low CO2 suggests metabolic acidosis.

  • Calcium & Phosphorus: important for bone-mineral balance; often shift in CKD.

  • Anion Gap (calculated): helps classify metabolic acidosis types.

  • Urine Albumin-to-Creatinine Ratio (ACR): detects albumin leakage (A1 <30, A2 30–299, A3 ≥300?mg/g).

  • Urinalysis with Microscopy: blood, protein, glucose, casts (RBC casts suggest glomerular disease), crystals (stone risk), infection clues.

  • Optional context tests: Magnesium, uric acid, serum/urine osmolality, urine sodium (for select acute evaluations).

Quick Build Guide

Clinical goal Start with Add if needed
Wellness baseline Renal function panel (eGFR/creatinine, BUN, Na/K/Cl, CO2) • Urinalysis • Urine ACR Calcium/Phosphorus
Diabetes or hypertension routine screen eGFR • Urine ACR • Urinalysis Cystatin C (borderline eGFR) • A1c • Lipid panel
Acute illness or dehydration / AKI question Renal panel • Urinalysis Urine sodium/osmolality • Serum osmolality • CK (if muscle injury suspected)
Medication monitoring (drugs that affect kidneys/electrolytes) Renal panel (focus on K? and CO2) Magnesium per clinician
CKD follow-up eGFR • ACR • Electrolytes • CO2 Calcium/Phosphorus • Intact PTH • 25-OH Vitamin D • CBC/Iron studies
Stone-prone or gout context Renal panel • Urinalysis (pH, crystals) Uric acid • 24-hr stone profile(recurrent stones)

How the Testing Process Works

  1. Select your starting set: most people begin with a renal function panel, urine ACR, and urinalysis.

  2. Provide samples: clean-catch urine and a standard blood draw; no fasting unless lipids/glucose are included.

  3. Confirm persistence: repeat eGFR/ACR over ≥3 months to confirm CKD vs. temporary changes.

  4. Broaden if needed: add cystatin C, bone-mineral markers, anemia/iron studies, or stone/UTI tests based on findings.

  5. Review & plan: discuss results with your clinician; imaging or specialist referral may be recommended.

Interpreting Results (General Guidance)

  • eGFR: generally normal at ≥90; <60 for ≥3 months supports CKD. Falling trends raise concern.

  • ACR: A1 (<30?mg/g) normal-mild; A2 (30–299) moderate; A3 (≥300) severe—higher categories increase risk at any eGFR.

  • BUN/Creatinine pattern: both high may reflect reduced filtration; BUN-predominant elevations can occur with dehydration or high protein intake.

  • Potassium: elevated K? can be urgent in CKD; low K? may occur with losses or certain medicines—always interpret with a clinician.

  • Bicarbonate/CO2: low CO2 suggests metabolic acidosis, common in advanced CKD.

  • Calcium/Phosphorus: abnormal patterns point toward bone-mineral imbalance.

  • Urinalysis clues: RBC casts/dysmorphic RBCs suggest glomerular disease; nitrite/leukocyte esterase favor infection; crystals suggest stones.
    Always interpret patterns over time with a qualified healthcare professional.

Choosing Panels vs. Individual Tests

  • Foundational kidney panel: eGFR (creatinine) • BUN • Na/K/Cl • CO2 • Calcium/Phosphorus

  • Refinement/confirmation: Cystatin C eGFR when creatinine-based eGFR is borderline or muscle mass is atypical.

  • Damage detection: Urine ACR and urinalysis to uncover albumin/protein or blood in urine.

  • Complication checks: Electrolytes/CO2, PTH/25-OH Vitamin D, CBC/Iron studies, uric acid as clinically indicated.

FAQs

Do I need to fast for a renal function panel?
No. Fast only if your order includes lipids or fasting glucose.

Why would I add cystatin C?
It can confirm or refine eGFR, especially when creatinine is borderline or muscle mass is unusual.

How often should I test if I have diabetes or high blood pressure?
Often yearly for eGFR, ACR, and urinalysis; more often if abnormal or high-risk.

Can dehydration change my results?
Yes. Dehydration can raise BUN and affect creatinine and ACR. Rehydration and repeat testing may be needed.

What if my potassium is high?
High K? can be serious. Contact your clinician promptly—do not make changes without medical advice.

Is a normal eGFR enough to clear me?
Not always. ACR and urinalysis can detect kidney damage even when eGFR looks normal.

When should I see a kidney specialist?
Consider referral for eGFR <30, A3 albuminuria, rapid decline, resistant hypertension, or unclear cause—your clinician will guide you.

Related Categories & Key Tests

  • Kidney & Urinary Health Tests Hub

  • Kidney Disease Tests • Kidney Health Tests • Protein in Urine (Proteinuria) • Blood in Urine (Hematuria) • Kidney Stone Risk • Hypertension Tests • Diabetes Health

  • Key Tests: Renal Function Panel (eGFR/Creatinine, BUN, Na/K/Cl, CO2) • Calcium • Phosphorus • Cystatin C (eGFRcys) • Urine ACR • Urinalysis with Microscopy • Magnesium • Uric Acid • Serum/Urine Osmolality • Urine Sodium • Intact PTH • 25-OH Vitamin D • CBC • Iron/TIBC • Ferritin • Transferrin Saturation

References

  • KDIGO — Evaluation and Management of Chronic Kidney Disease.
  • National Kidney Foundation (KDOQI) — CKD detection, staging, and laboratory assessment.
  • American Diabetes Association — CKD screening and monitoring in diabetes.
  • American Heart Association — Hypertension and kidney disease risk statements.
  • ASN/ACP — Use of cystatin C to confirm eGFR.
  • Clinical laboratory texts — Interpretation of electrolyte and acid–base testing in kidney disease.

Available Tests & Panels

Your Renal Function Tests menu is pre-populated in the Ulta Lab Tests system. Start with a renal function panel, then add cystatin C, urine ACR, and urinalysis for a fuller picture. Use filters to include bone-mineral markers, anemia/iron studies, or stone/UTI tests as needed. Follow collection instructions and review results with your clinician to confirm findings, stage risk, and plan monitoring.

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The Liver Function Panel, also known as a Hepatic Function Panel, measures proteins, enzymes, and bilirubin to assess liver health and function. It helps detect liver disease, monitor liver conditions, and evaluate the effects of medications or other factors on liver performance.

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Also Known As: Hepatic Function Panel Test, HFP Test
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The Liver and Kidney Function Panel measures blood sugar, electrolytes, proteins, and markers of liver and kidney health. It helps detect disease, monitor conditions, and guide treatment decisions.

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The Albumin 24 Hour Urine with Creatinine Test measures albumin and creatinine excretion over 24 hours to evaluate kidney function. Elevated albumin (albuminuria) may signal early kidney disease, diabetes-related damage, or hypertension. By comparing albumin to creatinine, this test accounts for urine concentration and improves accuracy. Doctors use it to detect kidney injury, monitor chronic disease, and guide treatment or prevention strategies.

Urine
Urine Collection
Also Known As: Urine Albumin Test, 24 Hour Microalbumin Test
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The Albumin 24 Hour Urine Test evaluates the amount of albumin released in urine during a full day, serving as an indicator of kidney health. High albumin levels can signal early kidney damage from diabetes, hypertension, or chronic kidney disease. Collecting urine over 24 hours improves accuracy by reflecting daily fluctuations, offering important insight for detecting renal impairment, monitoring progression, and supporting long-term care.

Urine
Urine Collection
Also Known As: Urine Albumin Test, 24 Hour Microalbumin Test
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The Albumin Random Urine Test measures the amount of albumin, a protein that can leak into urine when the kidneys are damaged. Elevated levels may indicate early kidney disease, often linked to diabetes, hypertension, or other chronic conditions. Doctors use this test to detect albuminuria, monitor kidney function, and guide treatment strategies. A random urine sample makes it a convenient tool for screening and long-term kidney health assessment.

Urine
Urine Collection
Also Known As: Urine Albumin Test, Random Microalbumin Test
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The Albumin Random Urine Test with Creatinine measures albumin and creatinine levels in a urine sample to evaluate kidney health. Elevated albumin (microalbuminuria) may indicate early kidney disease, diabetes complications, or hypertension-related damage. Doctors use this test to detect kidney problems before symptoms appear, monitor chronic conditions, and guide treatment. It provides vital insight into renal function and long-term kidney disease management.

Urine
Urine Collection
Also Known As: Urine Albumin Test, Random Microalbumin Test, uACR Test
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The Albumin Timed Urine Test measures albumin levels excreted during a set time period to evaluate kidney function and detect early protein loss. Elevated results may indicate diabetic nephropathy, hypertension-related damage, or glomerular disease. This test supports monitoring of renal health, guiding detection of microalbuminuria and helping assess risks of chronic kidney disease or cardiovascular complications.

Urine
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Also Known As: Urine Albumin Test, Timed Microalbumin Test
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The Albumin Creatinine Ratio Timed Urine Test measures albumin and creatinine levels in a timed urine sample to evaluate kidney function. Elevated albumin excretion can indicate early kidney damage, diabetic nephropathy, or hypertension-related disease. By analyzing the albumin-to-creatinine ratio, this test provides insight into kidney filtration, urinary protein loss, and overall renal health monitoring.

Urine
Urine Collection
Also Known As: Urine Albumin Test, Timed Microalbumin Creatinine Ratio Test
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The Neopterin Serum Test measures levels of neopterin, a marker released by activated macrophages in response to interferon-gamma. Elevated concentrations reflect immune system activation and may indicate viral infections, autoimmune disease, cancer, or transplant rejection risk. This test helps clinicians assess cellular immune response, track inflammatory activity, and evaluate disease progression or treatment monitoring.

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The Prolactin, Dilution Study measures prolactin levels using dilution techniques to correct assay interference. This test improves accuracy when unusually high prolactin is present, distinguishing genuine hyperprolactinemia from laboratory artifact. It aids in evaluating pituitary adenomas, reproductive hormone imbalance, infertility, and endocrine-related disorders with reliable, clinically useful results.

Blood
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The Protein Total 24-Hour Urine with Creatinine Test measures the amount of protein and creatinine excreted in urine over 24 hours. Elevated protein levels may indicate kidney disease, diabetic nephropathy, hypertension, or other renal disorders. Doctors use this test to evaluate kidney function, detect proteinuria, and monitor treatment response. Combining protein and creatinine helps ensure accurate results, making it essential for assessing long-term kidney health.

Urine
Urine Collection
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The Protein Total Random Urine with Creatinine Test measures protein and creatinine levels in a single urine sample to evaluate kidney function. Elevated protein may signal kidney disease, diabetes complications, or hypertension-related damage. Doctors order this test for patients with swelling, high blood pressure, or abnormal lab results. Results help detect proteinuria, assess renal health, and guide treatment or monitoring of chronic kidney conditions.

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The PTH Intact Test measures intact parathyroid hormone (PTH) levels in blood to evaluate parathyroid gland function and calcium balance. Abnormal PTH may indicate hyperparathyroidism, hypoparathyroidism, kidney disease, or vitamin D imbalance. Doctors use this test to investigate osteoporosis, kidney stones, or unexplained calcium abnormalities. Results provide vital insight into endocrine function, bone metabolism, and overall calcium regulation.

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Blood Draw
Also Known As: Parathyroid Hormone Intact test, Intact PTH test, Parathormone Test
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The Blood Urea Nitrogen (BUN) Test measures urea nitrogen levels in blood to assess kidney function and how well the body removes waste. Elevated BUN may indicate kidney disease, dehydration, heart failure, or high protein intake, while low levels may suggest liver disease or malnutrition. Doctors order this test to evaluate fatigue, swelling, or abnormal lab results. Results help diagnose kidney and liver conditions and guide treatment decisions.

Blood
Blood Draw
Also Known As: BUN Test, Blood Urea Nitrogen Test
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The Urea Nitrogen 24 Hour Urine Test measures nitrogen excreted over a full day to evaluate protein metabolism and kidney function. Elevated levels may reflect high protein intake, catabolic states, or certain metabolic conditions, while decreased levels can indicate malnutrition, liver disease, or impaired renal function. This test provides valuable insight into nutritional balance, metabolic health, and renal performance.

Urine
Urine Collection
Also Known As: 24 Hour Urine Urea Nitrogen Test
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The Urea Nitrogen Random Urine Test measures nitrogen excretion from protein metabolism to help evaluate kidney function, hydration status, and nutritional balance. Abnormal results may reflect renal impairment, dehydration, liver disease, or malnutrition. By analyzing a single urine sample, this test provides insights into metabolic health and supports assessment of protein utilization and overall renal function.

Urine
Urine Collection
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The Uric Acid Test measures uric acid levels in blood to assess kidney function and detect gout, a form of arthritis caused by uric acid buildup. High levels may also signal kidney disease, kidney stones, or metabolic disorders, while low levels can occur with liver disease. Doctors use this test to investigate joint pain, swelling, or frequent urination, and to monitor treatment for gout, kidney stones, or chemotherapy-related complications.

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Also Known As: Serum Urate Test
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The Urinalysis Test with Reflex to Microscopic screens urine for abnormalities in color, clarity, pH, protein, glucose, blood, and more. If results are abnormal, a microscopic exam is performed to detect cells, bacteria, crystals, or casts. Doctors order this test to evaluate urinary tract infections, kidney disease, diabetes, or metabolic disorders. Results provide essential insight into urinary tract and overall renal health for diagnosis and monitoring.

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 The Urinalysis Complete and Uric Acid Panel is a diagnostic tool combining a comprehensive Urinalysis Complete with a Uric Acid test to assess kidney function, detect urinary tract disorders, and evaluate uric acid levels in the blood, which can contribute to conditions like gout and kidney stones.
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The Urinalysis Macroscopic Test examines urine for color, clarity, and appearance to help identify possible kidney or urinary tract issues. Abnormal results may indicate infection, dehydration, liver disease, or metabolic conditions. Doctors use this test as a first step in evaluating urinary symptoms, monitoring overall health, or detecting early signs of medical problems that may require further testing and treatment.

Urine
Urine Collection
Also Known As: Urinalysis Test, UA Test, Urine Macroscopic Examination Test, Macroscopic Urinalysis Test
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The Urinalysis Microscopic Test examines urine under a microscope to detect cells, crystals, casts, bacteria, and other substances. Doctors use this test to evaluate urinary tract infections, kidney disease, or metabolic disorders. It helps identify causes of blood in urine, proteinuria, or abnormal results from standard urinalysis. Results provide valuable insight into kidney function, urinary tract health, and underlying medical conditions requiring further care.

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Also Known As: Microscopic Urinalysis Test
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Everything About Renal Function Decline and Lab Tests

An estimated 37 million people in the United States have kidney disease, and 1 out of 2 people have impaired renal function and don't even realize that they do.

For this reason, renal function lab tests are crucial in managing your overall kidney health. And if you're at risk for developing kidney disease, you need as much knowledge as possible. A renal function panel is a perfect way to start.

Sometimes your kidneys can fail, and your renal function declines. It's essential to have the education and tools you need to manage your kidney health. Keep reading this guide to learn everything you need to know about kidney decline and renal function tests.

What is Renal Function Decline?

Your kidneys are amazing organs, and they work hard to keep the balance of your body in check. They maintain a balance in the body by regulating water and minerals like sodium and potassium. Your kidneys are also responsible for removing waste from your blood after digestion, medication, or chemical exposure.

Your kidneys are even responsible for making chemicals to help with red blood cell production, along with vitamin D.

Renal function decline is the gradual loss of your kidney function, either from disease or other factors. When you have kidney disease, it affects your body's ability to clean and filter your blood. 

When your kidneys get damaged, waste products build up in your blood, causing symptoms of kidney failure.

The main types of kidney disease are acute and chronic kidney disease. Both acute and chronic diseases have different causes, from injury to illness.

Acute Kidney Disease

If your kidneys stop working suddenly, it's called an acute renal failure or acute kidney injury. The leading causes of acute kidney failure include:

  • Decrease in blood flow to the kidneys
  • Damage to the kidneys
  • Urine that is backed up in the kidney

Most often, acute kidney failure is caused by blood loss from a traumatic injury, dehydration, severe infection, taking certain medications, or complications from pregnancy.

People with autoimmune disease, heart, or liver failure are more likely to develop acute kidney failure.

Chronic Kidney Disease

Doctors will classify this as chronic kidney disease if your kidneys don't function normally for three months or more. Often you don't have any symptoms in the early stages of the disease, but this is also when it's much easier to treat. 

The most common conditions over time that harm your kidneys are diabetes and high blood pressure. Other conditions that can cause kidney failure and kidney disease include:

  • Autoimmune diseases like lupus
  • Viral illnesses like HIV, AIDS, and hepatitis B and C
  • Kidney infection or a urinary tract infection that leads to kidney damage
  • Inflammation in the glomeruli (tiny filters) in your kidneys
  • Polycystic kidney disease is genetic and causes fluid-filled sacs on your kidneys

If you have kidney abnormalities at birth, they block your urinary tract and affect kidney function. Toxins, drugs, and long-term use of ibuprofen or any anti-inflammatory drug can cause kidney damage over time.

Kidney Cancer

Another thing that causes kidney function decline is kidney cancer. The most common type of kidney cancer is renal cell carcinoma. Children can also develop a type of kidney cancer called Wilms' tumor.

Kidney cancer is thought to have a genetic cause, but if you have long-term dialysis for kidney failure, you're at greater risk for developing kidney cancer overall.

Risk factors for Renal Function Decline

Your most significant risk factors for a decline in renal function include diabetes and high blood pressure, but there are other risk factors including:

  • Genetics. Having immediate family members with kidney disease increases your risk.
  • Being over 60 years old
  • Being African American, Hispanic, Native American, or Asian American

Causes of Renal Function Decline

Diabetes and high blood pressure are not only your biggest risk factors. They are also the biggest causes of renal function decline. Other conditions that can cause kidney failure ad kidney disease include:

  • Polycystic kidney disease
  • Glomerulonephritis
  • An acute kidney injury that causes kidney damage
  • Autoimmune diseases
  • Kidney cancer

Signs and Symptoms of Renal Function Decline

Your kidneys can adapt and compensate for a long time before you get symptoms of kidney disease. Most of the time, kidney damage happens so slowly that you won't feel any symptoms until the advanced stages. Symptoms you'll notice include:

  • High blood pressure
  • Loss of appetite
  • Weakness and fatigue
  • Nausea and vomiting
  • Metallic tase
  • Trouble concentrating
  • Trouble sleeping
  • Muscle cramps
  • Swelling in your feet, ankles, or legs
  • Chest pain and shortness of breath
  • Itching

How Is a Decline In Renal Function Diagnosed?

Your first step towards a diagnosis is making an appointment with your doctor to discuss your symptoms and medical and family history. 

Your doctor will perform a physical exam and check for problems with your heart or high blood pressure. Your doctor will also likely order blood tests and a urine test to assess your kidney function.

Depending on what your initial tests show, you may also have to have imaging tests to look at your kidneys or a kidney biopsy of a piece of your kidney tissue to determine what's causing your problems.

Lab Tests to Monitor Renal Function

The best test to evaluate and monitor your renal function is a renal function panel. This panel measures your BUN/Creatinine Ratio, which helps determine your kidney function and what conditions may be causing a decrease in blood flow to the kidneys. A renal function panel also checks your glucose, calcium, and electrolyte levels.

Another test helpful in screening and monitoring a known or suspected kidney disease is the cystatin C with eGFR test. Cystatin C is a small protein found throughout your body and filtered from the blood by your kidneys. This test measures the amount of cystatin in your body.

High protein concentrations in your urine are a sign of kidney disease. A protein total and random urine with creatinine test measure the amount of protein present.

A complete blood count (CBC) is also important as it measures your red blood cells and the overall health of your blood.

FAQS about Renal Function

Are you wondering how you know if you have kidney disease? Since there are often no signs or symptoms initially, it's essential to have both blood and urine tests to check.

How can you protect your kidneys in the best way? The best way to protect your kidneys is to evaluate your lifestyle habits and make the changes you need. Stop smoking, keep your blood sugar in range if you have diabetes, and focus on a healthy diet and exercise.

What type of doctor specializes in treating kidney problems? A nephrologist will treat you if you've been diagnosed with kidney disease. 

Renal Function Lab Tests With Ulta Lab Tests

Ulta Lab Tests offers tests that are highly accurate and reliable so that you can make informed decisions about your health. Here are a few great things to love about Ulta Lab Tests:

  • You'll get secure and confidential results
  • You don't need health insurance
  • You don't need a physician's referral
  • You'll get affordable pricing
  • We offer a 100% satisfaction guarantee

Order your renal function lab tests today, and your results will be provided to you securely and confidentially online in 24 to 48 hours for most tests.

Take charge of your health and order from Ulta Lab Tests today!