High creatinine on your blood test — what it means and when to push

Your bloodwork came back and one line was flagged: creatinine high, or eGFR low. Your GP glanced at it and said the words that leave so many people uneasy — "we'll keep an eye on it, let's monitor." You went home and typed "high creatinine" into a search bar and found a wall of frightening results about kidney failure and dialysis. This article is written to do the opposite: to explain, calmly and specifically, what a high creatinine actually means, when "monitor" is genuinely the right call, and when it is fair — and important — to push for more.

What creatinine actually is

Creatinine is a waste product. Your muscles produce it continuously as a by-product of normal energy use, and your kidneys filter it out of your blood into your urine. Because that production is fairly steady, the level in your blood becomes a useful window into how well your kidneys are filtering. When the kidneys slow down, creatinine builds up — so a higher blood creatinine can mean the kidneys are clearing it less efficiently.

That is why labs rarely stop at the creatinine number. They feed it — along with your age and sex — into a formula that produces your eGFR, or estimated glomerular filtration rate. Think of eGFR as a percentage-style estimate of your kidney filtration capacity: a number around 90 or above is normal, and lower numbers indicate reduced filtration. Creatinine and eGFR move in opposite directions: as creatinine rises, eGFR falls. So "high creatinine" and "low eGFR" are usually describing the same finding from two angles.

A single high reading is not a diagnosis

This is the single most important thing to understand, and the reason panic is usually premature. One raised creatinine, taken on one day, can be caused by things that have nothing to do with long-term kidney disease:

• Dehydration — the most common transient cause. Concentrated blood shows a higher creatinine that corrects once you rehydrate.
• A recent high-protein meal or a creatine supplement — a big steak dinner or gym supplements the day before can nudge the number up.
• Recent heavy exercise — intense muscle activity releases more creatinine temporarily.
• Certain medications — NSAIDs (ibuprofen, naproxen), some blood pressure medications, and others can raise creatinine, sometimes reversibly.
• An acute illness — infection, vomiting, or diarrhoea can temporarily reduce kidney filtration.

On the other hand, a high creatinine can genuinely reflect chronic kidney disease (CKD) — a gradual, ongoing reduction in kidney function. The problem is that a single snapshot cannot tell these two stories apart. A transient spike and the early phase of CKD can look identical on one blood test. That is exactly why the right next step is almost never to worry — or to shrug — but to repeat the test and look at the trend.

The right next step: repeat it, and add a urine test

Two tests turn a single confusing number into an actual picture of your kidney health.

1. Repeat the creatinine and eGFR — establish the trend

A trend beats a snapshot every time. If your creatinine was high because you were dehydrated or had eaten a large protein meal, a repeat test done properly hydrated will often be normal. If it stays elevated, that tells you something real. And if you have several past results on file, the most valuable question of all is: is my eGFR stable, or is it drifting down over months and years? A stable, mildly reduced eGFR is a very different situation from one that is steadily falling.

2. Urine ACR — the test creatinine alone can miss

The urine albumin-to-creatinine ratio (ACR) checks for albumin — a protein — leaking into your urine. Healthy kidneys keep protein in the blood; when the filtering units are damaged, protein leaks through. A raised ACR is one of the earliest and most important signs of kidney damage, and it can be present even when your eGFR still looks reasonable. This is why a nephrologist looks at eGFR and ACR together: they answer two different questions — how well are the kidneys filtering, and are they being damaged. Skipping the ACR is one of the most common gaps in how a high creatinine gets worked up.

When "monitor" is genuinely the right call

Here is the reassuring part, because it applies to a lot of people. Monitoring is a legitimate, evidence-based plan when all of the following are true:

• Your eGFR is only mildly reduced and stable over time — for example stage G2 or G3a, which is common and often ages with people without ever causing trouble.
• Your urine ACR is normal — no significant protein leaking, meaning no active damage signal.
• Your blood pressure and blood sugar are well controlled, since these are the two biggest drivers of kidney decline.

If that describes you, "we'll monitor" is not a brush-off — it is exactly right. Many people live long, healthy lives with a mildly reduced eGFR that never progresses. In that situation, periodic rechecks and keeping blood pressure and diabetes in good control genuinely is the whole plan. You do not need a specialist, and you do not need to worry.

When to push — and what "push" actually means

Monitoring becomes less reassuring, and worth questioning, when the picture is not stable and clean. It is entirely reasonable to go back to your GP and ask whether a nephrology referral is warranted — or to seek a specialist opinion — if any of these apply:

• Your eGFR is falling over successive tests. A downward trend, even from a "not that bad" starting point, is the thing that matters most. Direction beats the single value.
• Your eGFR is below 30. This is a recognised threshold where specialist nephrology input is generally appropriate rather than watchful waiting alone.
• Your urine ACR is raised. Significant proteinuria signals active kidney damage and changes the whole picture — it warrants more than passive monitoring.
• There is blood in your urine (haematuria). Blood plus protein together is a combination that deserves prompt investigation.
• Your blood pressure is uncontrolled. Persistently high blood pressure both damages kidneys and is a sign the situation is not being managed.
• You have symptoms — swelling in the legs or around the eyes, foamy urine, unusual fatigue, or a marked change in how much you are passing urine.

"Pushing" does not mean being difficult with your GP. It means asking specific, informed questions: "Can we repeat this to see the trend?" "Have we checked my ACR?" "Given my eGFR is dropping, is it time for a nephrology referral?" A good GP welcomes that — it helps them justify escalating your care. Wait times to see a nephrologist in the public system can be long, so knowing early whether you genuinely need one is valuable in itself.

What to ask your GP — a short checklist

If you take nothing else from this article, take these questions to your next appointment:

• Can we repeat the creatinine and eGFR to establish my trend rather than relying on one reading?
• Can we do a urine ACR to check for kidney damage?
• Can we review my medications — am I on NSAIDs or blood pressure drugs that could be affecting the number?
• Have we ruled out reversible causes like dehydration or a recent illness?
• What is my eGFR trend, and what is my ACR? — the two answers that actually matter.

Why this matters more for South Asians

There is a specific reason a high creatinine deserves closer attention in the South Asian community. South Asians carry a substantially higher risk of both Type 2 diabetes and high blood pressure — the two leading causes of chronic kidney disease worldwide — and they develop diabetes at lower body weight and younger age than the general population. Diabetic kidney disease, in particular, is more common and can progress faster. That combination means a raised creatinine or a rising eGFR in a South Asian patient should be taken seriously and worked up properly, not dismissed as a one-off.

This isn't cause for alarm — it is cause for attention. If you have a South Asian background and diabetes or high blood pressure in the family, our companion piece on kidney disease risk in South Asians in Canada goes deeper into why the risk is elevated and what to watch for.

Getting a nephrologist's eyes on your results

If your GP has said "monitor" and you are not sure that is enough — or you simply want to understand your numbers before your next appointment — a specialist opinion can settle it. Public nephrology waits in Canada are long; our guides to nephrologist wait times across Canada and, if you are in BC, nephrologist wait times in BC lay out what to expect.

Through Ginie Health, you can upload your creatinine, your eGFR history, and your urine ACR, and within 6 hours, for $45 CAD, receive a written clinical opinion from a nephrologist trained at PGIMER Chandigarh or AIIMS — among the finest medical institutions in the subcontinent. The opinion tells you what your trend actually means, whether monitoring is appropriate for your specific numbers, which tests to push for, and exactly what to say to your GP. It doesn't replace your Canadian care — it makes sure the "monitor" plan is the right one, and helps you push at the right moment if it isn't. If you'd rather talk it through, a live video consultation is available for $75 CAD. No referral required for either.