If you’ve been told you have CKD, or suspect you might, you need more than just a stage number. In our webinar “Not All CKD Is the Same—Why Cause Matters,” Dr. Brent Miller, a leading nephrologist, broke down why knowing the underlying cause of your CKD is essential for effective treatment. Whether you’re a patient, caregiver, or advocate, this session offered practical guidance on what questions to ask, what tests might matter, and why “just having CKD” isn’t a real diagnosis.*

What Is CKD—and Why Definitions Have Evolved

You might think of CKD as a single disease, but it’s actually a final result of many possible underlying conditions. Dr. Miller stressed that the kidney care world has changed dramatically:

“CKD is not one disease. It is a result of another disease process,” he said.

We used to think in binary terms: kidney failure or no kidney failure. But now, CKD is understood as a spectrum of decline and damage that can be staged and, in some cases, reversed or slowed down.

The CKD staging system, based on your estimated glomerular filtration rate (eGFR), helps measure where your kidneys are functionally, but it doesn’t explain why they’re there in the first place.

The Kidney Does More Than Make Urine

It’s easy to forget how many vital roles your kidneys play. Beyond filtering waste, your kidneys:

• Regulate blood pressure
• Manage salt, water, acid, and electrolytes
• Control red blood cell production (anemia)
• Activate vitamin D
• Help clear medications

As Dr. Miller put it:

“Every person who has high blood pressure has an issue with the kidneys in one way or another.”

That’s why CKD can show up in many different forms depending on which part of the kidney is affected.

CKD Has Many Causes—And You Deserve to Know Yours

If you’re leaving your doctor’s office with a diagnosis of just “CKD,” something’s missing.

“The next appointment needs to be a longer conversation,” Dr. Miller emphasized.

Some of the most common causes of CKD include:

• Diabetes (accounts for nearly 40–50% of CKD cases)
• Hypertension
• Autoimmune diseases like lupus or IgA nephropathy
• Genetic disorders like polycystic kidney disease or Alport syndrome
• Medication toxicity
• Cancer-related damage
• Obstructive issues like kidney stones or enlarged prostates

In some cases, you may have multiple contributing factors, which is why diagnosis matters so much.

Dr. Miller also highlighted the importance of newer tools:

“There are blood and cheek swab tests that can screen for over 390 genetic kidney diseases.”

Why Knowing the Cause Matters More Than Ever

Twenty years ago, knowing the cause may not have made a big difference. That’s no longer true.

“In the last 5 to 7 years, we’ve had dramatic introductions to new medicines,” said Dr. Miller.

Knowing your CKD type can:

• Guide treatment decisions
• Help predict progression
• Avoid unnecessary worry if your decline is age-related and stable
• Determine if you’re eligible for targeted therapies
  

What You Should Be Asking Your Doctor

Dr. Miller listed five questions that every patient with CKD should walk out of the clinic understanding:

1. What caused my CKD?
2. What is my current kidney function?
3. What is my prognosis?
4. What is my treatment plan?
5. What’s the backup plan if my kidneys fail?

“Don’t walk out of a nephrologist’s office with your diagnosis being CKD, stage whatever. That is a mistake.”

These questions can guide both you and your care team toward more personalized, effective care.

Understanding GFR and CKD Staging—But Not Over-Relying On It

GFR (glomerular filtration rate) is a critical tool, but it has limits:

• It fluctuates daily depending on hydration, diet, and more.
• It’s an estimate (eGFR), not an exact number.
• A low GFR in an 85-year-old might be normal aging, not disease.
• GFR doesn’t tell you what’s causing the decline.

So while your CKD stage matters, it should never replace knowing the cause.

Early Intervention Changes Everything

“The earlier you catch it, the better the outcome,” said Dr. Miller.

Using a chart of CKD progression curves, Dr. Miller showed how early treatment could completely change the course of the disease:

• Intervening early can mean never needing dialysis.
• Waiting too long often means starting dialysis in crisis, at the ER.

And for many with diabetes-related kidney disease, new medications can reduce the need for dialysis by up to 30%.

When to See a Nephrologist

According to Dr. Miller, here are signs you should see a nephrologist:

• eGFR below 60 with no clear cause
• Protein or blood in your urine
• Multiple risk factors (diabetes, high BP, chemo history)
• You’re not getting clear answers from your doctor

“Get a diagnosis. Don’t settle for a stage number.”

Even a one-time visit can give you clarity and direction.

In Summary

If you or a loved one has CKD, you deserve more than a label. You need to know the cause. That’s what drives effective treatment, realistic planning, and long-term quality of life.

And remember, you don’t have to be a doctor to advocate for yourself. Bring your lab results. Ask the hard questions. Request a second opinion if needed.

Because not all CKD is the same—and neither are the outcomes.

*Responsum Health. (2025, August 27). Not All CKD is the Same. Why Cause Matters. 

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