A Complete Guide To How To Get Your Kidneys Checked And Understand The Results

Your kidneys silently filter about 120 to 150 quarts of blood each day, removing waste and excess fluid from your body. When kidney function declines, symptoms often don’t appear until damage is advanced. That’s why proactive screening and understanding your results are critical. Millions of people have chronic kidney disease (CKD) without knowing it. This guide walks you through how to get your kidneys tested, what each test reveals, and how to interpret the numbers so you can take informed action.

Why Kidney Health Matters

Kidney disease increases the risk of heart attack, stroke, and premature death. Unlike the liver or skin, kidneys don’t regenerate. Once damaged, they rarely recover fully. Early detection allows for lifestyle changes and medical interventions that can slow or halt progression. High-risk groups—including those with diabetes, high blood pressure, a family history of kidney failure, or over age 60—should be especially vigilant.

“Early detection of kidney disease can prevent the need for dialysis or transplant down the line.” — Dr. Lena Patel, Nephrologist, Johns Hopkins Medicine

Step-by-Step: How to Get Your Kidneys Checked

Getting your kidneys evaluated involves a combination of blood work, urine tests, and sometimes imaging. Here’s how to proceed:

1. Request a Kidney Function Panel: During your annual physical, specifically ask your doctor for kidney function tests. Don’t assume standard blood panels include all necessary markers.
2. Provide a Urine Sample: A simple dipstick test or a 24-hour urine collection can detect protein leakage, an early sign of kidney damage.
3. Review Blood Test Results: Key indicators include creatinine, estimated glomerular filtration rate (eGFR), and blood urea nitrogen (BUN).
4. Discuss Risk Factors: Share your full medical history, including hypertension, diabetes, medication use, and family history.
5. Follow Up as Needed: If results are abnormal, your doctor may order additional tests like ultrasound or refer you to a nephrologist.

Tip: Bring a list of all medications and supplements to your appointment—some, like NSAIDs, can harm kidneys over time.

Key Tests and What They Measure

Understanding your lab report starts with knowing which values matter most.

Test	What It Measures	Normal Range	What Abnormal Means
eGFR (estimated Glomerular Filtration Rate)	How well your kidneys filter waste	90+ mL/min/1.73m²	<60 for 3+ months indicates CKD
Serum Creatinine	Waste product from muscle metabolism	0.7–1.3 mg/dL (men), 0.6–1.1 mg/dL (women)	Elevated levels suggest reduced filtration
Urine Albumin-to-Creatinine Ratio (UACR)	Protein leakage into urine	<30 mg/g	30–300 = microalbuminuria; >300 = macroalbuminuria
Blood Urea Nitrogen (BUN)	Nitrogen waste from protein breakdown	7–20 mg/dL	High levels may indicate dehydration or kidney dysfunction

The eGFR is the most important number. It’s calculated using your creatinine level, age, sex, and race (though newer formulas are moving away from race-based adjustments). A declining eGFR over time signals worsening kidney function.

Interpreting Your Results: Stages of Kidney Disease

Kidney disease is classified into five stages based on eGFR. Knowing your stage helps determine treatment urgency.

• Stage 1: eGFR ≥90 with signs of kidney damage (e.g., protein in urine)
• Stage 2: eGFR 60–89 with other evidence of damage
• Stage 3a: eGFR 45–59
• Stage 3b: eGFR 30–44
• Stage 4: eGFR 15–29 — time to prepare for possible dialysis
• Stage 5: eGFR <15 — kidney failure, requiring dialysis or transplant

If your eGFR is below 60 for three months or more, you meet the criteria for chronic kidney disease. However, not everyone with low eGFR progresses to failure. The presence of protein in urine significantly increases risk.

Tip: Track your eGFR annually if you’re over 50 or have diabetes/hypertension—even if past results were normal.

Real Example: Catching Damage Early

Carlos, a 58-year-old with type 2 diabetes, went for his routine checkup. His primary care physician included a UACR test despite Carlos feeling fine. The result showed 85 mg/g—indicating moderate protein leakage. His eGFR was 78, within normal range but lower than the year before. Further evaluation revealed uncontrolled blood sugar and slightly elevated blood pressure.

Carlos started a stricter glucose management plan, added an ACE inhibitor (which protects kidneys), and began monitoring at home. One year later, his UACR dropped to 28 mg/g, and his eGFR stabilized. Without that early urine test, damage could have progressed unnoticed.

Common Misconceptions About Kidney Testing

Several myths delay proper care:

• Myth: “If I feel fine, my kidneys must be okay.” Reality: Kidneys can lose up to 90% of function before symptoms arise.
• Myth: “Only older people need kidney checks.” Reality: Young adults with diabetes or high blood pressure are at risk too.
• Myth: “Drinking more water will fix poor kidney function.” Reality: Hydration supports kidneys but can’t reverse structural damage.

Checklist: What You Should Do Now

Take control of your kidney health with this actionable checklist:

• ☑ Ask your doctor for a comprehensive kidney panel at your next visit
• ☑ Ensure the panel includes eGFR, serum creatinine, and UACR
• ☑ Share any history of diabetes, hypertension, or family kidney disease
• ☑ Avoid NSAIDs (ibuprofen, naproxen) unless approved by your doctor
• ☑ Monitor blood pressure and blood sugar if you have either condition
• ☑ Schedule annual follow-ups if you're at risk or have early-stage CKD

Frequently Asked Questions

Can kidney damage be reversed?

In early stages, progression can often be slowed or halted with proper management of blood pressure, blood sugar, and lifestyle factors. However, once significant scarring occurs, it is usually irreversible.

Do I need to fast before a kidney function test?

Most blood tests for kidney function do not require fasting, but some labs may request it. Always confirm with your provider. For a 24-hour urine collection, follow instructions precisely to ensure accuracy.

Is a low-protein diet good for kidney health?

For people with existing CKD, a moderate reduction in protein intake may reduce strain on the kidneys. However, healthy individuals should not restrict protein unnecessarily. Consult a dietitian familiar with kidney conditions before making major dietary changes.

Protecting Your Kidneys Long-Term

Beyond testing, daily habits shape kidney health. Stay hydrated, eat a balanced diet rich in fruits and vegetables, exercise regularly, and avoid smoking. Medications like ACE inhibitors or ARBs are often prescribed for those with proteinuria because they reduce intraglomerular pressure and protect filtration units.

Be cautious with supplements and herbal products—some, like aristolochic acid (found in certain traditional remedies), are directly toxic to kidneys. Always disclose supplement use to your healthcare provider.

Final Thoughts: Take Charge Before Symptoms Appear

Your kidneys don’t come with warning lights. By the time fatigue, swelling, or shortness of breath occur, significant damage may already exist. The power lies in prevention and early insight. Whether you're managing a chronic condition or simply aiming to stay healthy, requesting a kidney function test is one of the most impactful things you can do for long-term wellness.

💬 Your kidneys work for you every day—return the favor. Schedule your kidney check today, review your latest lab results, and share this guide with someone who needs it.