Kidney Disease Prevention: The Blood Tests That Catch It Early

Quick answer

The earliest warning signs of kidney disease are a falling eGFR, a rising creatinine, and a high urine albumin-to-creatinine ratio, or ACR. Standard panels track creatinine and eGFR. Urine ACR often gets skipped, even though it is one of the earliest signs of kidney damage from diabetes or high blood pressure. Yearly testing works for most adults. Test every 6 months if you have diabetes or high blood pressure.

Why CKD gets missed until it is late

There are three main reasons.

1. No symptoms until late. Your kidneys have a huge amount of spare capacity. Signs such as tiredness, swelling, foamy urine, or less urine than usual often stay hidden for years. They tend to show up only after you lose over half of your kidney function.
2. Normal ranges hide the trend. A drop from an eGFR of 120 to 90 is a 25% loss of function. Yet both numbers still read as "normal" on a report.
3. Standard panels often skip urine ACR. This urine test catches the earliest sign of kidney damage from diabetes and high blood pressure. Without it, that early warning gets missed.

The tests that detect kidney disease

Creatinine

Standard range: men 0.7 to 1.3 mg/dL, women 0.6 to 1.1 mg/dL.

Creatinine is a waste product your muscles make. On its own, it does not tell the full story. Your doctor also needs your age, sex, and body build to read it well. A creatinine of 1.1 can mean very different things in different people.

eGFR (estimated glomerular filtration rate)

Standard range: above 90 mL/min/1.73m² is normal.

Your eGFR is a number worked out from your creatinine, age, and sex. It shows how well your kidneys filter your blood. Doctors use it to stage kidney disease.

The trend matters most. A drop of more than 5 points a year is a real warning sign, even if each single reading still looks "normal."

BUN (blood urea nitrogen)

Standard range: 7 to 20 mg/dL. This can shift with how much water you drink, how much protein you eat, gut bleeding, or your kidney function.

Uric acid

Standard range: under 7.0 for men, under 6.0 mg/dL for women. This often rises along with kidney problems, and a high level can raise kidney disease risk on its own.

Cystatin C (an advanced test)

This is a more sensitive filtration marker than creatinine. It is less swayed by muscle mass. It helps when creatinine-based eGFR is unclear, such as in older adults, very muscular people, or people who have lost muscle.

Urine albumin-to-creatinine ratio (ACR)

Standard range: under 30 mg/g.

This test checks for tiny amounts of a protein called albumin leaking into your urine. This leak is often the earliest sign of kidney damage from diabetes or high blood pressure. It can show up before your eGFR ever drops. This is a urine test, not a blood test. It is easy to miss if your doctor does not order it by name.

Who faces higher risk

• Diabetes, the leading cause of CKD around the world.
• High blood pressure, especially when it is poorly controlled. Our guide to high blood pressure explains why this matters so much for your kidneys.
• Family history of kidney disease.
• Heart disease, including heart failure.
• Long term use of NSAIDs, common pain relievers such as ibuprofen.
• Traditional or herbal medicines, since some contain compounds that harm the kidneys.
• Repeated kidney stones.
• Older age.
• Smoking.
• Obesity, which raises risk on its own.

Common patterns

Pattern 1: Early decline

• Creatinine slowly rising over the years.
• eGFR slowly drifting down, such as 105, then 95, then 88.
• Both readings still marked "normal" on the report.
• What to do: work on blood pressure and blood sugar control. Review any medicines that stress the kidneys. Ask about a urine ACR test.

Pattern 2: Diabetic kidney disease

• Diabetes or prediabetes already diagnosed.
• Urine ACR above 30 mg/g.
• eGFR may still look normal.
• What to do: tighten blood sugar and blood pressure control. Your doctor may prescribe an ACE inhibitor or ARB, two types of blood pressure medicine that also protect the kidneys. A kidney specialist visit may help.

Pattern 3: High blood pressure related damage

• Ongoing high blood pressure.
• Falling eGFR.
• Mild protein in the urine.
• What to do: keep tight control of blood pressure, often with an ACE inhibitor or ARB.

Pattern 4: Dehydration look-alike

• High BUN.
• Mildly high creatinine.
• A BUN to creatinine ratio above 20 to 1.
• What to do: drink more water, then retest. This pattern usually clears up on its own.

Pattern 5: Advanced CKD

• eGFR under 60, staying there over time.
• Often with anemia, high phosphorus, or high uric acid.
• What to do: see a kidney specialist for a full workup.

How to protect your kidneys

1. Keep tight control of blood pressure

Aim for under 130/80 mmHg. This is the single most powerful step for kidney protection.

2. Keep tight control of blood sugar if you have diabetes

Set your HbA1c target with your doctor. For most people with diabetes, this target is under 7%.

3. Avoid medicines that stress the kidneys, when you can

NSAIDs, such as ibuprofen and naproxen, can build up damage over time with regular use. Certain antibiotics, contrast dyes for scans, and some herbal products can too. Ask your doctor about safer options.

4. Stay well hydrated

Drinking enough water supports normal filtering. Pale yellow urine is a simple, practical sign that you are drinking enough.

5. Cut back on salt

This matters even more in Filipino diets, which often run high in sodium.

6. Lose extra belly fat

Obesity raises CKD risk on its own, separate from other factors.

7. Ask about ACE inhibitors or ARBs if you are at risk

Some people with diabetes or high blood pressure also have protein in their urine. For them, these medicines protect kidney function. This is a decision to make with your doctor.

8. Treat sleep apnea

Untreated sleep apnea is linked to faster kidney decline on its own.

9. Stop smoking

Smoking speeds up the loss of kidney function.

10. Be careful with herbal products

Many traditional herbal remedies can harm the kidneys. Always tell your doctor about any herbal supplements you take.

How often to test

• Healthy adult, no risk factors: once a year.
• Diabetes or high blood pressure: creatinine and eGFR every 6 months, urine ACR once a year.
• Known CKD: every 3 months.
• After starting a medicine that could stress the kidneys: retest 4 to 6 weeks later.

When to see a specialist

Talk to a kidney specialist, or your regular doctor, if any of these apply:

• Your eGFR stays under 60.
• Your eGFR is dropping more than 5 points a year.
• Your urine ACR stays above 30 mg/g.
• You see blood in your urine along with a high creatinine.
• Your creatinine rises suddenly, a sign of acute kidney injury.

How &you Labs handles kidney testing

Every &you Labs panel checks creatinine, eGFR, BUN, and uric acid. Urine ACR is available as an add-on, and we recommend it for anyone with diabetes, high blood pressure, or other risk factors. Cystatin C is available for very muscular people, athletes, or other cases where creatinine-based eGFR may be unreliable. Your report also tracks your trend across past panels, since the trend matters more than any single number.

Your kidneys are one filter. Your liver is the other. Bilirubin is a liver marker worth reading next.

If you want to see where your kidney markers stand, you can book a full panel. Your results come back with both the standard range and the healthy target range, side by side.

Frequently asked questions

My creatinine is "normal" but keeps rising. Is that a problem?

Yes. The trend matters more than any single reading. A creatinine that moves from 0.9 to 1.1 over a few years is a real signal, even if both numbers are technically normal.

Can kidney function come back?

Sudden kidney injury, from medicines, dehydration, or illness, often heals fully. Established CKD usually does not reverse, but the rate at which it worsens can be slowed a great deal with good care.

Should I take protein supplements if I have early kidney disease?

Normal amounts of protein are fine for most people, including those with early CKD. Very high protein diets are sometimes limited in advanced CKD. In early disease, a normal diet is usually fine.

Are kidney tests reliable for very muscular people?

Creatinine based eGFR can understate kidney function in very muscular people. More muscle means more creatinine, no matter how well the kidneys filter. Cystatin C gives a more accurate picture in this case.

Will PhilHealth cover kidney testing?

Basic kidney tests, such as creatinine and urinalysis, are often covered under standard outpatient packages. Coverage rules change over time. It is best to confirm with PhilHealth directly. More advanced tests, such as cystatin C or urine ACR, are usually paid out of pocket.

Key takeaways

• Kidney function can decline for years without any symptoms, until the disease is advanced.
• The earliest warning signs are a rising creatinine, a falling eGFR, and a high urine albumin-to-creatinine ratio.
• Test once a year if you are healthy, or every 6 months if you have diabetes or high blood pressure.
• The best protections are tight blood pressure and blood sugar control, avoiding NSAIDs, cutting salt, staying hydrated, and losing extra belly fat.
• Cystatin C and urine ACR can add useful detail beyond a standard panel.