Was the Initial CKD Stage 2 Diagnosis Incorrect?
The initial diagnosis of CKD stage 2 was likely incorrect because CKD stages 1 and 2 absolutely require documented evidence of kidney damage (such as albuminuria, imaging abnormalities, or biopsy findings) in addition to the eGFR value—an eGFR of 60-89 mL/min/1.73 m² alone is insufficient for diagnosis. 1, 2, 3
Understanding the Diagnostic Requirements
CKD Stage 2 Criteria
- Stage 2 CKD requires BOTH components: eGFR 60-89 mL/min/1.73 m² AND evidence of kidney damage persisting for at least 3 months 1, 3
- Evidence of kidney damage includes:
The Critical Diagnostic Error
- The most common misdiagnosis occurs when clinicians diagnose CKD based on eGFR alone without confirming kidney damage 2, 3
- Your nephrologist appears to have made this exact error if no evidence of kidney damage was documented 2
Do You Currently Have CKD?
With eGFR of 64 mL/min/1.73 m²
You do NOT have CKD if there is no evidence of kidney damage, as your eGFR of 64 mL/min/1.73 m² falls within the stage 2 range (60-89 mL/min/1.73 m²), which requires additional proof of kidney damage for diagnosis. 3, 4
Important Considerations About eGFR Fluctuations
- eGFR variability is common and does not necessarily indicate disease progression or improvement 1
- Your eGFR fluctuations (60s → upper 50s → 60s-70s → 64) suggest:
The 3-Month Rule for Chronicity
- CKD diagnosis requires abnormalities persisting for at least 3 months 1, 4
- A single abnormal eGFR could represent:
Addressing Your Specific Questions
Did You Have CKD Stage 3a?
No, you did not have CKD stage 3a when your eGFR fell to the upper 50s. While stage 3a is defined as eGFR 45-59 mL/min/1.73 m², this stage can be diagnosed by eGFR alone only if it persists for >3 months. 3, 4 However, since your eGFR subsequently improved back to the 60s-70s, this was likely:
Did You Ever Have CKD?
Based on the information provided—that there was "absolutely no evidence of kidney damage"—you never had CKD. 2, 3 The diagnosis was based solely on eGFR values in the 60s, which is insufficient for CKD stage 2 diagnosis. 1
What Should Have Been Done
Proper Diagnostic Workup
- Measure urine albumin-to-creatinine ratio (UACR) on at least 2 of 3 specimens over 3-6 months 1
- Obtain kidney imaging (ultrasound) to assess for structural abnormalities 1
- Review past eGFR measurements to establish chronicity 2, 4
- Consider measuring cystatin C to confirm eGFR accuracy, especially if eGFR is 45-59 mL/min/1.73 m² 4
Confirming True CKD vs. Normal Aging
- In individuals ≥70 years, an eGFR of 45-59 mL/min/1.73 m² that is stable over time without other evidence of kidney damage may represent normal aging rather than CKD 5
- The controversy exists whether eGFR <60 mL/min/1.73 m² alone should define CKD, particularly in elderly individuals 1
Common Pitfalls to Avoid
- Never diagnose CKD stages 1-2 based on eGFR alone 2, 3
- Do not assume a single abnormal eGFR represents chronic disease 2, 4
- Recognize that eGFR equations have limitations in certain populations (elderly, extreme body composition, variable muscle mass) 1, 4
- Understand that biological variability can cause eGFR fluctuations of 10-15% without true change in kidney function 1
Current Recommendation
Request documentation from your nephrologist regarding evidence of kidney damage (UACR results, imaging findings, or biopsy results). If no such evidence exists and your eGFR remains ≥60 mL/min/1.73 m², you do not meet criteria for CKD and the diagnosis should be reconsidered. 2, 3, 4