Low eGFR: What to Do After a High Creatinine Result

Your blood test came back with creatinine marked high or an eGFR below the printed range, and you want to know what happens now. Talk the result through with your doctor, who will interpret it. One result is not a diagnosis: your doctor repeats the test, checks your urine and looks for a cause. You can keep the first report and the repeat in a folder or in Sam's Health Vault, your own copy for your own use, not linked to an electronic patient record. There, once you consent, Sam takes values such as creatinine and eGFR from a photo or PDF.

What the numbers mean, and how the G1 to G5 stages work, is covered in kidney test results explained. This article is about the path from a first abnormal result to a diagnosis: what is urgent, what gets checked and when a specialist comes in. What Sam keeps for this condition is on the chronic kidney disease page.

Abnormal kidney results with symptoms: when is it urgent?

Early kidney disease usually causes no symptoms. It is often found on a blood or urine test done for another reason, says the NHS. If symptoms come with the result, do not wait for the next check:

• Sudden or severe trouble breathing, chest pain or confusion: call your local emergency number (112 in the EU, 999 in the UK, 911 in the US).
• Clearly less urine than usual, new swelling, breathlessness when you lie down, rapid weight changes, ongoing vomiting or diarrhea, or blood in your urine: ask for an urgent appointment with your doctor today. Out of hours, use your local urgent care line, such as NHS 111 in the UK. The German GP guideline says visible blood in the urine always needs to be looked into.
• Any other new symptom: contact your doctor promptly rather than waiting for the repeat test.

Do not wait for it to pass. This list also applies while you wait for a planned repeat test. If symptoms get worse, do not wait for the three months to pass.

If your doctor suspects acute kidney disease, the German GP guideline (DEGAM) says to recheck eGFR within two weeks. With fluid build-up or breathlessness, an immediate referral or hospital admission may be needed instead.

Does one abnormal result mean kidney disease?

Not on its own. The international KDIGO guideline defines chronic kidney disease (CKD) as changes in kidney structure or function. They must last at least three months and have implications for health. It says not to assume chronic disease from a single eGFR or urine result. The cause could be a recent acute kidney injury.

The high or low label on your report only compares the value with your lab's reference range. The guideline sorts results differently, using an eGFR cut-off of 60 and the albumin in your urine. So a slightly high creatinine is not automatically kidney disease. A value inside the range is no all-clear either. The German GP guideline notes that creatinine only rises late.

A borderline result is read against your earlier results and your urine test. The guideline cut-offs are for doctors. They are not a test you can run on your own report.

Can high creatinine be temporary?

Yes. Creatinine is not a pure kidney marker. The German GP guideline lists influences that can shift it without the kidneys filtering less:

• A lot of muscle or very little, for example from bodybuilding, muscle disease or paralysis.
• An unusual body build.
• A high-protein diet and creatine supplements.
• Some medicines that reduce how much creatinine is cleared.
• Interference in the lab measurement.

A raised result can also mean acute kidney injury. That is when the kidneys suddenly stop working as well as they should. The NHS lists dehydration, low blood pressure, blood loss, infections and long-term use of some medicines among the causes. Many people have no symptoms, especially when it is mild.

Only the repeat test shows whether a result was temporary. So tell your doctor what happened in the days before the blood test: an infection, vomiting or diarrhea, hard exercise, a new medicine or a supplement. Whether a medicine plays a part, and whether it needs changing, is your doctor's call. Some over-the-counter products, especially certain painkillers, can harm the kidneys, so check with your clinic before taking them.

What does your doctor check after a first low eGFR?

KDIGO says to establish the cause from your history, family history, medicines, an examination, lab tests and imaging. One detailed version comes from the German GP guideline (DEGAM, 2024, written with the German nephrology society). It adapts KDIGO and the UK NICE guideline for primary care. For a first eGFR below 60, it describes these steps:

1. A second eGFR after three months, or earlier if an acute problem is suspected. It tells chronic disease apart from an acute problem or normal variation.
2. A urine albumin-to-creatinine ratio (ACR). Creatinine and eGFR alone are not enough to judge the kidneys, the guideline says.
3. A urine dipstick for blood. A positive strip should be checked with a second, independent test.
4. A blood pressure check. High blood pressure can be both a cause and a result of kidney disease.
5. One ultrasound of the kidneys and urinary tract.

High blood pressure and diabetes are the most common causes, according to the German GP guideline's patient leaflet. Before a new medicine is prescribed, including an over-the-counter one, the guideline asks for two checks: does it suit your kidney function, and does the dose need adjusting?

Why does confirming CKD take three months?

The three months are part of the definition. A change only counts as chronic once it has lasted that long. KDIGO lists several ways to show this, including earlier results and repeat tests within and beyond the three months.

So older lab reports may already hold part of the answer. Think of a routine check-up, a hospital stay or another clinic. How to request copies is covered in getting a copy of your medical records. If a symptom from the list above appears or gets worse before the repeat test, do not wait for the appointment.

In Sam, you add the first report and the repeat to the Health Vault. Sam compares your last two lab reports and shows up to three values that changed most. Creatinine or eGFR are not always among them. If a value is printed in different units on the two reports, Sam does not compare it.

Two limits matter here. Sam saves urine creatinine, and some ways of printing the albumin-to-creatinine ratio, as creatinine. The value list then simply calls them creatinine. In the comparison, Sam can set such a urine value against your blood creatinine when both carry the same unit. If either report has a urine creatinine row, do not rely on the comparison for creatinine. Check the original report (photo or PDF). If your lab prints separate ranges for women and men, Sam keeps only the first one. The high, low or in-range label can then be wrong. The original report is what counts, and whether your kidney function has changed is for your doctor to judge.

Who looks after this, and when do you see a nephrologist?

Your first point of contact is usually your GP or primary care doctor. KDIGO says testing for kidney disease should mostly happen in primary care and other specialties, not only with kidney specialists. A kidney specialist is a nephrologist. KDIGO lists situations for referral to specialist kidney care. Examples are an eGFR below 30, a lot of albumin in the urine, an uncertain cause or blood pressure that stays high despite four or more medicines. National guidelines set their own detail. If the ultrasound suggests a blockage, the referral goes to urology.

The reasons, the nephrologist's role and the first visit are explained in why was I referred to a nephrologist?. These criteria are for your doctor. They are not a test you run on your own report, and missing one is no all-clear. If you are unsure, ask whether a referral makes sense for you.

Would you notice if your kidneys were struggling?

Usually not at first. The NHS says there are usually no symptoms in the early stages. In stages 1 to 3, reduced kidney function can only be found with a blood test, says the German GP guideline's patient leaflet. At a more advanced stage, the NHS lists tiredness, swollen ankles, feet or hands, shortness of breath, feeling sick and blood in the urine. Sudden or severe breathlessness belongs on the do-not-wait list above.

Because early stages are silent, KDIGO supports testing people at high risk, including those with high blood pressure, diabetes or heart disease. The German GP guideline recommends a creatinine and eGFR test when diabetes or high blood pressure is first diagnosed. If you were just told you have high blood pressure, see high blood pressure diagnosis: what now.

A smartwatch cannot help with this question. Creatinine, eGFR and urine albumin are measured in a lab from blood and urine. Sam does not measure kidney values and does not read any from Apple Health.

What to have ready for the workup

• Older lab reports with creatinine or eGFR, including ones from other clinics or a hospital. They can show how long a result has been like this.
• A list of everything you take, including over-the-counter and herbal products and supplements. See what to put on a medication list.
• Notes on the days before the blood test: an infection, vomiting or diarrhea, hard exercise, a new medicine.
• Kidney disease in your family, as far as you know.
• Your questions: When is the repeat test? Will I have a urine test and an ultrasound? Would a referral to a nephrologist make sense for me?

You can keep that list in Sam's medication list. The catalog and its suggestions are a selection, not a recommendation. Picking an entry prefills a pack strength, so check it against your pack. Sam does not check interactions.

Keep your first and repeat kidney reports in Sam

At the repeat test, your first report, older results and medicines are in one app, instead of sheets from different clinics.

• Instead of a folder: in the Health Vault, Sam takes values such as creatinine, eGFR and urea from a photo or PDF once you consent. You can check and edit every row before saving.
• Instead of comparing two printouts: Sam compares your last two lab reports and shows up to three values that changed most.
• Instead of a paper list: the medication list keeps everything you take, including over-the-counter products you use as needed.

Sam does not know urine albumin as a value of its own, saves urine creatinine as creatinine and may compare it with your blood creatinine, and leaves what a result means to your doctor. More on the chronic kidney disease page.

Try Sam for free

Sam is a wellness companion, not a medical device. The app does not diagnose, treat, cure or prevent any disease or health condition. Always consult qualified professionals for medical decisions.

Related reading

• Kidney test results explained: creatinine, eGFR, albumin
• Why was I referred to a nephrologist? What to expect
• Medication list for your doctor: what to include
• Getting a copy of your medical records when changing doctor
• High blood pressure diagnosis: what now?
• Doctor appointment checklist for a chronic condition

Sources

Updated: October 2026

• KDIGO: KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease, Kidney International 2024;105(4S):S117-S314 (introduction on screening in primary care, definition, Practice Points 1.1.3.1, 1.1.3.2 and 1.1.4.1 with Figure 8, rationale to 2.1.1 to 2.1.3, Practice Point 5.1.1 with Figure 48)
• DEGAM/DGfN: S3 guideline on chronic kidney disease not requiring dialysis in primary care, long version (AWMF 053-048, version 2.0, 2024; key recommendations, chapter 6 with recommendations 6.1 to 6.14, Table 7 on sources of eGFR error, haematuria section, Figure 3 and Table 10 on referral; German)
• DEGAM: Patient information, CKD stages 1-3 (version 2.0, 2024, with the German kidney patients' association; German)
• NHS: Kidney disease and Kidney disease: diagnosis (last reviewed 22 March 2023), Acute kidney injury (last reviewed 11 March 2026), Blood in urine (last reviewed 25 September 2026)
• IQWiG (gesundheitsinformation.de): Chronic kidney disease (updated 14 August 2024; German)