If asked which organ is responsible for filtering roughly 180 litres of fluid per day, regulating blood pressure, controlling electrolyte balance, producing hormones that maintain red blood cell production, activating vitamin D for bone health, and maintaining acid-base balance across the entire body — most people wouldn’t immediately name the kidneys. But all of this is what your two kidneys are doing, quietly and constantly, for as long as they’re functioning well.
When kidneys start to fail, the failure is usually slow and silent. Unlike, say, the heart (which announces problems with chest pain or palpitations) or the liver (which eventually causes jaundice), the kidneys can lose substantial function — often 50% or more — before any noticeable symptoms appear. The condition this slowly produces, chronic kidney disease (CKD), affects an estimated 10-15% of Malaysian adults, with substantial numbers undiagnosed.
The reason CKD matters isn’t just kidney failure at the far end (though that’s serious — dialysis or transplantation become the only options). The reason it matters is that kidney disease at any stage substantially increases cardiovascular risk, often interacts with diabetes and hypertension in damaging ways, and can be slowed or stabilised when caught early. This article walks through what kidney function tests actually reveal, who should be tested, and what to do with various findings.
Why Malaysian Adults Are at Particular Risk
Several factors converge to make chronic kidney disease unusually common in Malaysian populations:
High diabetes prevalence.
Diabetes is the leading cause of chronic kidney disease globally. With approximately 1 in 5 Malaysian adults having diabetes, the population-level kidney disease burden is substantial. Diabetic kidney disease (diabetic nephropathy) develops in a significant proportion of diabetics over years, often silently in its early stages.
High rates of hypertension.
Hypertension is the second leading cause of chronic kidney disease. Many Malaysian adults have undiagnosed or inadequately controlled hypertension, contributing to silent kidney damage over time.
Cardiovascular disease overlap.
Cardiovascular and kidney disease share risk factors and often coexist. Each substantially worsens the other.
Heavy use of certain medications.
Non-steroidal anti-inflammatory drugs (NSAIDs like ibuprofen, naproxen, mefenamic acid), certain antibiotics, and various herbal supplements can damage kidneys over time. Widespread NSAID use for muscle aches, joint pain, and headaches contributes to kidney damage in some patients.
Specific population factors.
Genetic factors, dietary patterns, and lifestyle factors specific to Asian populations interact with kidney health in ways that are still being studied.
End-stage kidney disease rates.
Malaysia has substantial numbers of patients on dialysis, with rates that have grown over the past few decades. Many of these patients were diagnosed late — kidney disease that could potentially have been slowed if identified earlier.
Who Should Be Tested
Several groups particularly benefit from kidney function testing:
All diabetic patients.
Annual kidney function assessment (including urine albumin testing) is standard for diabetic care. Catches diabetic kidney disease at early stages when interventions can substantially slow progression.All patients with hypertension.
Annual kidney function testing is part of comprehensive hypertension management. Kidney status influences blood pressure medication choices.Adults over 50.
Routine kidney function assessment as part of general health screening. Catches age-related decline and various other causes.Family history of kidney disease.
Some genetic conditions affect kidneys. Family history of polycystic kidney disease or other inherited kidney conditions warrants attention.Patients on long-term medications affecting kidneys.
NSAIDs, certain blood pressure medications, lithium, certain antibiotics, and various other medications can affect kidney function. Periodic monitoring is appropriate.Patients with cardiovascular disease.
Established heart disease often coexists with kidney disease. Mutual monitoring is appropriate.Patients with recurrent kidney stones.
Recurrent stones can contribute to kidney damage over time. Periodic assessment is important.Anyone with persistent urinary symptoms.
Recurrent UTIs, persistent unusual urine appearance, frequent urination patterns warrant investigation.
What Kidney Function Tests Actually Measure
Several markers together assess kidney function:
Creatinine.
Waste product from normal muscle metabolism, cleared by the kidneys. When kidneys lose filtering capacity, creatinine accumulates in the blood. Normal ranges vary by sex and muscle mass:
- Men: typically 60-110 µmol/L
- Women: typically 50-90 µmol/L
- Lower in patients with reduced muscle mass; higher in muscular individuals
Important caveat.
Creatinine levels depend on muscle mass. A muscular man with creatinine of 110 may have completely normal kidney function; a frail elderly woman with creatinine of 90 may have substantial kidney dysfunction. Creatinine alone is incomplete — this is why eGFR (which accounts for these factors) is more clinically useful.
Estimated glomerular filtration rate (eGFR).
Calculated estimate of kidney filtering capacity. Adjusts creatinine for age, sex, and (in some calculations) race. The most clinically useful single measure of kidney function. Stages of chronic kidney disease:
- Above 90 mL/min/1.73m²: Normal kidney function (Stage 1 if other evidence of kidney disease, otherwise normal)
- 60-89: Mildly reduced (often normal for age, particularly elderly)
- 45-59: Mild to moderate kidney disease (Stage 3a)
- 30-44: Moderate kidney disease (Stage 3b)
- 15-29: Severe kidney disease (Stage 4)
- Below 15: Kidney failure (Stage 5) — typically requires renal replacement therapy
BUN (blood urea nitrogen) or urea.
Another waste product cleared by kidneys. Less specific to kidney function than creatinine — can also reflect dehydration, high protein intake, or certain medications. Reference range typically 2.5-7.5 mmol/L.
Electrolytes (sodium, potassium, chloride, bicarbonate).
Kidneys regulate these. Abnormalities can indicate kidney dysfunction or various other conditions. Potassium is particularly important — significant abnormalities can affect heart rhythm.
Urine albumin to creatinine ratio (uACR).
Urine test that detects small amounts of albumin (a protein) being lost in urine. Normally, kidneys retain albumin in the blood; leakage suggests kidney damage even when blood creatinine remains normal. Particularly important in diabetic patients:
- Below 30 mg/g (or 3 mg/mmol): Normal
- 30-300 mg/g (or 3-30 mg/mmol): Moderately increased albuminuria (microalbuminuria) — early sign of kidney damage
- Above 300 mg/g (or 30 mg/mmol): Severely increased albuminuria (macroalbuminuria) — more advanced damage
Urinalysis.
Basic urine test examining for blood, protein, glucose, and other findings. Provides general screening for various urinary tract issues.
Stages of Chronic Kidney Disease
CKD is staged based on eGFR and presence of other kidney damage indicators:
Stage 1 (eGFR ≥90 with kidney damage).
Normal filtering rate but evidence of damage (albuminuria, structural abnormalities, or other markers). Early intervention can prevent progression.
Stage 2 (eGFR 60-89).
Mildly reduced function. May or may not represent disease depending on context — often normal for age in older adults without other indicators.
Stage 3a (eGFR 45-59).
Mild to moderate reduction. Clearly meaningful kidney disease. Active management to slow progression becomes important.
Stage 3b (eGFR 30-44).
Moderate kidney disease. Significant functional impairment. Often referred to nephrologist for management.
Stage 4 (eGFR 15-29).
Severe reduction. Preparation for renal replacement therapy may begin. Nephrology care essential.
Stage 5 (eGFR <15).
Kidney failure. Dialysis or kidney transplantation needed for survival in most cases.
Progression isn’t inevitable.
Many patients with stage 1, 2, or 3 CKD remain stable for years or decades with appropriate management. The goal of identifying disease early is precisely to slow progression and prevent advancement to later stages.
What to Do With Abnormal Results
If your kidney function tests show abnormalities, several practical steps:
Confirm with repeat testing.
Single abnormal results sometimes don’t reflect true kidney function. Dehydration, recent intense exercise, certain medications, or acute illness can transiently affect results. Repeat testing in 1-3 months often clarifies.
Identify contributing factors.
Diabetes? Hypertension? NSAID use? Herbal supplements? Family history? Identifying contributors guides intervention.
Optimize diabetes and blood pressure control.
If diabetic or hypertensive, optimal control is the single most important intervention. Both substantially affect kidney disease progression. Specific medication classes (ACE inhibitors, ARBs, SGLT2 inhibitors) have particular kidney-protective effects for diabetic patients.
Review medications.
Avoid or minimise NSAIDs (use paracetamol for pain when possible). Review all medications for kidney-affecting potential. Some medications need dose adjustment based on kidney function.
Lifestyle modifications.
- Maintain hydration (but excessive water intake doesn’t help kidney function and can sometimes cause issues)
- Reduce sodium intake (helps blood pressure and may reduce kidney workload)
- Moderate protein intake (very high protein diets stress the kidneys; very low protein isn’t generally recommended either)
- Weight management if overweight
- Avoid herbal supplements without proper guidance (some herbal products are nephrotoxic)
- Limit alcohol
- Don’t smoke
Specialist referral when appropriate.
Significantly reduced kidney function (typically eGFR below 30, sometimes earlier), unexplained kidney disease, or rapidly progressing disease warrants nephrologist consultation.
Diabetic Kidney Disease — A Special Focus
Given the prevalence of diabetes in Malaysia, diabetic kidney disease deserves specific attention:
Often progresses silently.
Early diabetic kidney disease produces no symptoms. The first detectable sign is typically microalbuminuria (small amounts of albumin in urine) — visible only on testing, not in symptoms.
Progression timeline.
Without intervention, diabetic kidney disease typically progresses over 10-30 years from initial damage to advanced stages. With appropriate intervention, progression can be substantially slowed.
Key interventions.
- Tight blood sugar control (HbA1c targets individualised)
- Aggressive blood pressure control (often below 130/80 for diabetic patients)
- ACE inhibitor or ARB medications: substantial kidney protective effect
- SGLT2 inhibitors: relatively newer medication class with strong evidence for kidney protection in diabetes
- Specific dietary considerations
- Avoiding nephrotoxic medications
Regular monitoring.
All diabetic patients should have an annual eGFR plus urine albumin to creatinine ratio. This catches kidney disease at the earliest stages when interventions are most effective.
Acute vs Chronic Kidney Issues
Worth distinguishing between two different patterns:
Acute kidney injury (AKI).
Rapid loss of kidney function, typically over hours to days. Causes include severe dehydration, infection, certain medications, kidney stones blocking urinary flow, and various other conditions. Often reversible if caught and treated promptly. Different management from chronic disease.
Chronic kidney disease (CKD).
Gradual decline over months to years. The focus of most discussion in this article. Aim is to slow progression and manage complications rather than acute reversal.
CKD on AKI.
Patients with existing CKD can have superimposed acute episodes — for example, dehydration during severe illness causing further decline. Acute issues in patients with chronic disease need particular attention.
Common Misunderstandings
Several common misconceptions worth addressing:
“My kidneys are fine because I urinate normally.”
Urine production continues until very late stages of kidney disease. Normal urine volume doesn’t mean kidneys are filtering properly. Most early CKD has completely normal urine volume and appearance.
“I should drink more water to protect my kidneys.”
Adequate hydration is fine, but drinking excessive water doesn’t improve kidney function and can sometimes cause problems (particularly in patients with already impaired kidney function). Normal hydration is sufficient.
“Herbal supplements are safer than medications for my kidneys.”
Many herbal supplements can be nephrotoxic. Some traditional remedies have been associated with kidney damage. Discuss any herbal use with your doctor, particularly if you have existing kidney issues.
“Once kidney function declines, it can’t be improved.”
This is partly true — significant structural damage is generally not reversible. But progression can be slowed, function can be stabilised, and in early acute episodes function can often be restored. Early intervention matters substantially.
Get Kidney Health Assessment at Dr Prevents
If you haven’t had kidney function testing recently — particularly if you have diabetes, hypertension, family history of kidney disease, or you’re over 50 — please come in. At Dr Prevents, our KL and Selangor clinics offer comprehensive kidney health assessments including creatinine, eGFR, urine albumin to creatinine ratio, and urinalysis.
Most patients leave with reassurance that their kidney function is fine. The substantial minority with early CKD benefit from identification at stages where lifestyle interventions and appropriate medications can substantially slow progression. The smaller group with more advanced disease benefits from proper management to prevent further decline.
📞 Silent decline caught early. Walk in today. 🩺