High creatinine and kidney disease

When people see a high creatinine, the first worry is often "do I have kidney disease?". This page explains how clinicians answer that question. The short answer is that it takes more than one creatinine result. It needs eGFR, a urine test and, for chronic kidney disease, evidence over more than 3 months.

Short-term change or long-term condition?

A raised creatinine can reflect two very different situations.

• Acute kidney injury (AKI) is a sudden fall in kidney function that develops over hours or days. It is usually linked to an illness, dehydration, a medicine or a blockage. It needs prompt attention, and kidney function often improves once the cause is treated.
• Chronic kidney disease (CKD) is kidney damage or reduced function that has lasted for more than 3 months. It usually develops slowly, over years, and often causes no symptoms in its early stages.

A creatinine result on its own does not show which of these is happening, or whether either is. That is why earlier results are so valuable. If you have old reports from any hospital or lab, bring them.

How chronic kidney disease is defined

The KDIGO 2024 guideline defines CKD as abnormalities of kidney structure or function, present for more than 3 months, with implications for health. In practice, clinicians look for one or more of:

• an eGFR below 60 mL/min/1.73m²;
• albumin in the urine, with a urine ACR of 3 mg/mmol (30 mg/g) or more;
• other markers of kidney damage, such as certain findings on urine microscopy, on a kidney scan, or on a kidney biopsy.

So CKD can be present with a normal eGFR if there is persistent albuminuria. And a single low eGFR during an illness does not mean CKD if it recovers.

How CKD is staged: eGFR and albuminuria together

Once CKD is confirmed, KDIGO describes it using two measures. The G category comes from eGFR:

The A category comes from the urine ACR:

A person's CKD is described with both, for example "G3a A2". The combination gives a better picture of risk than either measure alone. Higher albuminuria and lower eGFR each add to the risk of kidney function falling further, and to the risk of heart disease. Read more in CKD stages.

Why creatinine alone is not enough

• Creatinine depends on muscle mass, diet, exercise and some medicines, not just the kidneys.
• It does not rise much until a fair amount of filtering has been lost, so early kidney damage can be missed.
• It gives no information about protein leaking into the urine.

This is why KDIGO recommends estimating GFR with a validated equation and measuring urine albumin, rather than relying on serum creatinine alone.

What tests help confirm or rule out kidney disease

• Repeat creatinine and eGFR, often at least twice over 3 months. See eGFR explained.
• Urine ACR, often repeated to confirm. See urine ACR test.
• Urinalysis, to check for blood and other signs. See urinalysis.
• Kidney ultrasound in some people. See kidney ultrasound.
• Cystatin C, in some cases where creatinine may be misleading.
• Tests for underlying causes, such as blood sugar and blood pressure.

If CKD is found

Being told you have CKD can be frightening. Many people with CKD, particularly in the earlier stages, never need dialysis. Care focuses on finding the cause, slowing any decline and lowering heart risk. A clinician may discuss blood pressure, blood sugar, medicines that protect the kidneys and heart, a review of medicines that may harm the kidneys, and how often to repeat tests. How often you are monitored depends on your eGFR and ACR categories. See monitoring CKD.

Many people with CKD are looked after by a general doctor or physician. Guidelines suggest specialist input from a nephrologist in some situations, for example an eGFR below 30, a high level of albumin in the urine, a fast fall in eGFR, or an unclear cause. Read when to see a nephrologist.

This page explains what a test or condition involves. It is not a diagnosis and does not replace advice from a doctor who knows your history. Your results should be interpreted together with your symptoms, other tests and a clinical assessment. Medical disclaimer.