Lab result explainedKidneyLast updated November 11, 2026

Creatinine clearance (CrCl): normal range, the Cockcroft-Gault formula and what a low result means

Creatinine clearance (CrCl) · Kidney function tests (serum creatinine with a 24-hour urine collection, or calculated from serum creatinine, age, weight and sex) · reported in mL/min (often reported as mL/min/1.73 m² when normalized to body surface area)

Creatinine clearance (CrCl) is an estimate of how many milliliters of blood your kidneys filter clean of creatinine every minute, and it is the oldest bedside measure of kidney filtration still in daily use. Creatinine is a waste product of muscle metabolism that the kidneys remove at a steady rate, so comparing how much appears in the urine with how much remains in the blood tells you how well the filters are working. Normal values are roughly 97 to 137 mL/min in men and 88 to 128 mL/min in women, falling by about 8 mL/min per decade after age 40.

There are two ways to get the number. The measured version collects every drop of urine for 24 hours and pairs it with a blood sample. The far more common version is the Cockcroft-Gault equation, which estimates CrCl from a single serum creatinine plus your age, weight and sex. That calculated number is what pharmacists and prescribers use to adjust doses of drugs that leave the body through the kidneys, including many antibiotics, blood thinners, metformin, gabapentin and chemotherapy, because most US drug labels were written using Cockcroft-Gault.

CrCl is closely related to, but not the same as, the eGFR printed on a routine metabolic panel. Both track glomerular filtration rate (GFR), the gold standard of kidney function, but CrCl runs 10 to 20 percent higher than true GFR because the kidney tubules secrete a little creatinine on top of what is filtered, and the two estimates can disagree substantially in people who are very large, very small, very muscular, frail or elderly. If your result is low, the first questions are whether it is new, whether it is stable, and whether the creatinine that went into it was affected by something other than your kidneys.

CrCl at a glance

  • What it is: the volume of blood plasma cleared of creatinine per minute, an estimate of kidney filtration rate (GFR).
  • Normal (adults): about 97–137 mL/min in men and 88–128 mL/min in women, often normalized to a 1.73 m² body surface area. Values decline with age; a healthy 75-year-old may run 60–80. Labs differ.
  • Cockcroft-Gault formula: CrCl = (140 − age) × weight in kg ÷ (72 × serum creatinine in mg/dL), multiplied by 0.85 for women.
  • Below 60 mL/min for more than 3 months fits chronic kidney disease stage 3; below 30 is stage 4; below 15 is kidney failure (stage 5).
  • CrCl overestimates true GFR by 10–20 percent, and more as kidney function falls; eGFR (CKD-EPI) is preferred for diagnosing and staging kidney disease, CrCl for drug dosing.
  • Next step: repeat if the sample or collection was doubtful, check eGFR, cystatin C, a urine albumin-to-creatinine ratio and blood pressure, and review medicines that need a dose change at your level.

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What CrCl measures

Creatinine is produced at a nearly constant rate from creatine in skeletal muscle, enters the blood, is freely filtered by the glomeruli and is not reabsorbed, so the amount leaving in urine per minute equals the amount filtered plus a small extra fraction that the proximal tubules actively secrete. Clearance is calculated as urine creatinine concentration multiplied by urine flow rate, divided by serum creatinine. For a 24-hour collection, if the urine creatinine is 120 mg/dL, the volume is 1,500 mL (1.04 mL/min) and the serum creatinine is 1.0 mg/dL, CrCl is 120 × 1.04 ÷ 1.0 = 125 mL/min. Labs then usually scale the result to a standard body surface area of 1.73 m².

The Cockcroft-Gault equation (1976) replaces the urine collection with age, weight and sex, which together approximate muscle mass and therefore creatinine production. Worked example: a 70-year-old woman who weighs 60 kg with a serum creatinine of 1.1 mg/dL has (140 − 70) × 60 = 4,200, divided by 72 × 1.1 = 79.2, giving 53 mL/min, times 0.85 for a woman = 45 mL/min. A 30-year-old man weighing 85 kg with the same creatinine of 1.1 has 110 × 85 = 9,350 ÷ 79.2 = 118 mL/min. The same creatinine value means a normal kidney in one person and stage 3b kidney disease in the other, which is why creatinine is never interpreted without age, sex and build.

Both methods inherit creatinine's weaknesses. Tubular secretion makes CrCl read about 10 to 20 percent above true GFR in healthy people and up to 50 percent above it in advanced kidney disease. Drugs that block secretion (trimethoprim, cimetidine, some HIV medicines) raise serum creatinine and lower calculated CrCl without any change in filtration. Muscle mass that is far from average, a high-meat meal, creatine supplements, amputation and liver disease all skew the serum value. And an incomplete 24-hour collection, the single most common error in the measured test, underestimates clearance: a complete collection should contain roughly 20 to 25 mg of creatinine per kg of body weight per day in men and 15 to 20 mg/kg in women.

Normal range for CrCl

Reference ranges vary between labs and by age, sex and pregnancy. Use the range printed on your own report.

GroupTypical range (mL/min (often reported as mL/min/1.73 m² when normalized to body surface area))Notes
Adult menAbout 97–137 mL/minTypical range quoted by US reference laboratories; some report 90–140. Labs differ.
Adult womenAbout 88–128 mL/minAbout 10 percent lower than men because of lower average muscle mass.
Effect of ageFalls about 6.5–8 mL/min per decade after the 30sA healthy 80-year-old commonly has a CrCl of 55–75 mL/min with no kidney disease. Cockcroft-Gault builds this decline in.
Kidney disease stage G2 (mildly decreased)60–89 mL/minOnly called kidney disease if there is also kidney damage (albuminuria, abnormal imaging or structural disease) for more than 3 months.
Stage G3a / G3b (moderately decreased)45–59 / 30–44 mL/minMany drug doses change below 50 and again below 30. Most people have no symptoms at this stage.
Stage G4 (severely decreased)15–29 mL/minNephrology referral, planning for possible dialysis or transplant, strict medication review.
Stage G5 (kidney failure)Below 15 mL/minDialysis or transplant is usually considered when symptoms or laboratory problems appear, typically below 10.
PregnancyRises 40–50 percent, often 150–200 mL/minNormal physiological hyperfiltration; serum creatinine falls to about 0.4–0.8 mg/dL. A 'normal' creatinine of 1.0 in pregnancy is abnormal.
Children (over 2 years)About 90–150 mL/min/1.73 m²Adult values are reached by about age 2; the Schwartz formula (height ÷ creatinine) is used rather than Cockcroft-Gault.

High creatinine clearance

A creatinine clearance above the reference range is far less common than a low one and is usually either real hyperfiltration or an artifact of how the number was produced. Real hyperfiltration (a GFR above about 130 to 140 mL/min/1.73 m²) happens in pregnancy, after a large protein meal, in the early years of type 1 and type 2 diabetes, in obesity and in people with a single kidney, where the remaining nephrons each filter more. In early diabetes, hyperfiltration is thought to stress the glomeruli and precede the later decline, which is one reason clinicians track the albumin-to-creatinine ratio closely in people whose eGFR looks 'too good'.

Artifacts are at least as frequent. The Cockcroft-Gault formula multiplies by total body weight, so in someone with obesity it overshoots badly; a 150 kg person is credited with the creatinine production of 150 kg of muscle. Pharmacists usually substitute an adjusted body weight (ideal body weight plus 40 percent of the excess) when actual weight exceeds ideal by more than 30 percent. In a 24-hour collection, a sample that includes urine from before the official start, or a timing error, inflates the result. Very low serum creatinine from low muscle mass (frailty, amputation, paralysis, advanced liver disease, malnutrition) also produces an artificially high clearance that does not reflect kidney health at all.

A high CrCl in a healthy young, well-muscled adult is not a problem and needs no action. In someone with diabetes, obesity or a single kidney it is a reason to look at albuminuria and blood pressure rather than to celebrate. In someone frail, it is a warning that creatinine-based estimates are unreliable in them and that cystatin C should be used instead; drug doses based on an inflated CrCl can be too high.

Common causes

  1. Pregnancy

    Plasma volume and renal blood flow rise from the first trimester, pushing GFR up 40 to 50 percent. Serum creatinine falls accordingly; values above about 0.9 mg/dL in pregnancy warrant evaluation.

  2. Early diabetes (hyperfiltration)

    Up to half of people with newly diagnosed type 1 and a smaller share with type 2 diabetes have a GFR above 130 to 140 mL/min/1.73 m², driven by high glucose, increased kidney size and altered tubular signaling. It tends to settle with good glucose control and is associated with later albuminuria if it does not.

  3. Obesity and the weight term in Cockcroft-Gault

    Fat mass does not make creatinine, so using actual body weight in the formula overstates clearance, sometimes by 30 to 60 percent. Obesity also causes genuine hyperfiltration through increased renal plasma flow.

  4. High protein intake and recent cooked meat

    A large protein load raises GFR for several hours, and cooked meat delivers preformed creatinine that temporarily raises serum creatinine; the net effect on a 24-hour clearance depends on timing, but high-protein diets raise measured clearance by 10 to 20 percent.

  5. Low muscle mass lowering serum creatinine

    Frailty, amputation, spinal cord injury, muscular dystrophy, cirrhosis and malnutrition all lower creatinine production, so a serum creatinine of 0.5 mg/dL yields a calculated clearance that looks excellent even when true GFR is reduced.

  6. Single kidney or kidney donation

    After donating a kidney, the remaining organ increases its filtration by about 30 to 40 percent within weeks (compensatory hyperfiltration), so clearance settles at roughly 65 to 75 percent of the pre-donation value rather than 50 percent.

  7. Over-collection or timing errors

    Including the first morning void that should have been discarded, or collecting for longer than 24 hours, adds creatinine that was not produced in the window and inflates the result.

  8. Drugs that increase tubular secretion or lower creatinine

    Fenofibrate raises creatinine (lowering clearance) but corticosteroids, which increase muscle breakdown, and some diuretics can move the number in either direction; always tell the lab what you take.

Symptoms that can go with it

  • Usually none; a high clearance is a laboratory finding rather than an illness
  • In early diabetes, increased urination and thirst from high glucose rather than from the kidney itself
  • Foamy urine if hyperfiltration has progressed to protein leak (albuminuria)
  • In pregnancy, the normal increase in urination frequency
  • Swelling of the ankles or around the eyes if a glomerular disease is the underlying cause

Low creatinine clearance

A low creatinine clearance means the kidneys are filtering less blood per minute than expected for your age, and the degree tells you how much. Values of 60 to 89 mL/min in an adult are only 'disease' if there is also evidence of kidney damage such as albumin in the urine; in people over 70, values in this band are common and often reflect normal aging. Below 60 mL/min that persists for more than three months defines chronic kidney disease (CKD) stage 3, which affects roughly one in seven US adults, most of whom do not know it. Below 30 is stage 4, where planning for the possibility of kidney failure begins, and below 15 is stage 5, kidney failure.

The two big questions are whether the fall is acute or chronic, and what is driving it. A sudden drop over days (acute kidney injury) is most often due to dehydration, low blood pressure, heart failure, a blocked urinary tract, sepsis or a nephrotoxic drug or contrast dye, and much of it is reversible if caught quickly. A slow decline over years is most often diabetes or high blood pressure, followed by glomerulonephritis, polycystic kidney disease, chronic obstruction and repeated kidney injury. Comparing today's value with previous creatinine results is the most useful single step; a stable CrCl of 50 for ten years is a very different situation from 50 that was 90 last year.

Low CrCl changes how medicines behave. Drugs cleared by the kidney accumulate, so doses of metformin, gabapentin and pregabalin, many antibiotics, direct oral anticoagulants, enoxaparin, digoxin, lithium and most chemotherapy are reduced or stopped at defined thresholds, commonly 50, 30 and 15 mL/min. NSAIDs (ibuprofen, naproxen), which reduce kidney blood flow, become more hazardous. If you take any regular medication and your clearance is below 60, a pharmacist or clinician should review the list.

Common causes

  1. Diabetes (diabetic kidney disease)

    The leading cause of CKD and kidney failure in the US, accounting for about 40 percent of new dialysis starts. Years of high glucose damage the glomerular filters; albuminuria usually appears before clearance falls.

  2. High blood pressure

    The second most common cause. Sustained pressure thickens and scars the small kidney arteries (nephrosclerosis), reducing filtration gradually. Each 10 mmHg reduction in systolic pressure slows the decline.

  3. Dehydration, vomiting, diarrhea and low blood pressure

    Less blood reaches the kidney, so filtration falls (prerenal injury). Clearance usually recovers within days of fluid replacement; a BUN-to-creatinine ratio above 20 points this way.

  4. Medicines and contrast dye

    NSAIDs, ACE inhibitors or ARBs combined with diuretics (the 'triple whammy'), aminoglycoside antibiotics, vancomycin, lithium, cisplatin, calcineurin inhibitors and iodinated contrast can each lower clearance; most effects are reversible if the drug is stopped early.

  5. Heart failure and cirrhosis

    Poor forward blood flow and neurohormonal activation reduce kidney perfusion (cardiorenal and hepatorenal syndromes). Creatinine-based estimates are also unreliable in cirrhosis because muscle mass is low.

  6. Urinary obstruction

    An enlarged prostate, kidney stones, strictures or a pelvic tumor backing urine up into the kidneys reduces filtration; a bladder scan or ultrasound finds it, and relieving the blockage often restores function.

  7. Glomerulonephritis and autoimmune kidney disease

    Lupus nephritis, IgA nephropathy, ANCA vasculitis and other immune diseases inflame the filters. Blood and protein in the urine alongside a falling clearance is the clue; a biopsy is often needed.

  8. Polycystic kidney disease and other inherited conditions

    Autosomal dominant polycystic kidney disease causes a steady decline, typically reaching kidney failure between ages 50 and 70; a family history and enlarged cystic kidneys on imaging make the diagnosis.

  9. Normal aging

    Nephron number falls by roughly a third between ages 30 and 80, so GFR declines by about 1 mL/min per year after 40 even in healthy people. Age-related decline without albuminuria carries a much lower risk than the same number in a 45-year-old.

  10. Drugs that block creatinine secretion (false low)

    Trimethoprim (in trimethoprim-sulfamethoxazole), cimetidine, cobicistat, dolutegravir and some other HIV medicines raise serum creatinine by 0.2 to 0.4 mg/dL without changing GFR, lowering the calculated clearance by 10 to 20 percent.

Symptoms that can go with it

  • None at all until clearance is well below 30 mL/min; most kidney disease is silent and found on blood tests
  • Swelling of the ankles, feet or around the eyes, especially in the morning
  • Foamy urine (protein), blood in the urine or a change in how much you pass
  • Fatigue, poor concentration and shortness of breath from anemia and fluid retention as clearance falls below 30
  • Nausea, loss of appetite, a metallic taste and itching when clearance is below about 15 (uremia)
  • Muscle cramps, restless legs and trouble sleeping in advanced disease
  • High blood pressure that is new or newly hard to control

Read it alongside

  • Serum creatinine — the input to every estimate; always interpret it with age, sex and muscle mass in mind.
  • eGFR (CKD-EPI 2021) — the preferred number for diagnosing and staging kidney disease; expect it to sit 10 to 20 percent below the measured CrCl.
  • Cystatin C — a filtration marker independent of muscle mass; used when creatinine is unreliable (frailty, amputation, bodybuilders, cirrhosis) and to confirm CKD stage 3a.
  • Urine albumin-to-creatinine ratio (UACR) — kidney damage shows here first; an ACR above 30 mg/g with a clearance of 60 to 89 confirms stage 2 CKD and raises cardiovascular risk.
  • BUN and the BUN-to-creatinine ratio — a ratio above 20 suggests dehydration or bleeding into the gut rather than intrinsic kidney disease.
  • Potassium, bicarbonate, phosphorus and hemoglobin — the complications that appear as clearance falls below 30 and guide treatment.
  • Urinalysis with microscopy — blood, protein and casts point to a glomerular cause that needs faster work-up.
  • Urine creatinine (24-hour total) — checks whether the collection was complete; a total far below 15 to 20 mg/kg suggests missed voids.

What usually happens next

  1. A single low value is confirmed with a repeat serum creatinine and eGFR, ideally when well hydrated and off NSAIDs, cimetidine, trimethoprim and creatine supplements for a few days; CKD requires abnormality for more than 3 months.
  2. Ask for a urine albumin-to-creatinine ratio, a urinalysis, blood pressure measurement, and a kidney ultrasound if the drop is new, large or unexplained; cystatin C is added when creatinine is likely misleading.
  3. Bring every medicine, including over-the-counter painkillers and supplements, to a pharmacist or prescriber for a dose review; the common thresholds for dose changes are 50, 30 and 15 mL/min.
  4. Gather previous creatinine values from old reports to establish the trajectory; a stable low value for years is managed differently from a rapid decline, which is usually referred to nephrology within weeks.
  5. If you are having a 24-hour collection, discard the first morning void, collect everything for exactly 24 hours including the next morning's first void, keep it refrigerated, and avoid heavy meat meals and intense exercise during the collection.
  6. For a clearance below 30, or below 45 with albuminuria, expect referral to a nephrologist and a discussion of blood pressure targets, SGLT2 inhibitors, and vaccination and dietary measures that slow progression.

Diet, lifestyle and natural levers with evidence

What can move CrCl once the cause is known. Nothing here replaces finding the cause.

Blood pressure control, including dietary sodium under 2 g a day

Strong evidence

Lowering blood pressure is the best-proven way to slow loss of clearance. In a Cochrane review of sodium restriction in CKD, cutting intake by about 2 g of sodium a day lowered systolic pressure by roughly 7 mmHg and albuminuria by about a third within weeks. The SPRINT trial found that a systolic target of 120 rather than 140 mmHg reduced deaths in people with CKD, and KDIGO now recommends a systolic target under 120 where tolerated. The DASH eating pattern lowers systolic pressure by 8 to 11 mmHg in people with hypertension.

Potassium-rich DASH-style diets and salt substitutes need a potassium check once clearance is below about 45 mL/min.

Moderate, plant-leaning protein intake (about 0.8 g/kg a day)

Moderate evidence

Very high protein intake raises filtration pressure in the remaining nephrons. A Cochrane review of 17 trials found that low-protein diets (0.5 to 0.6 g/kg) reduced progression to kidney failure in stage 4 to 5 CKD by about a third, with smaller and less certain effects in earlier stages. KDIGO advises 0.8 g/kg a day for adults with CKD not on dialysis, and against more than 1.3 g/kg. Observational studies link plant-based protein to slower decline than animal protein at the same intake.

Protein restriction below 0.8 g/kg should only be done with a renal dietitian, because malnutrition in CKD worsens outcomes. People on dialysis need more protein, not less.

Weight loss when BMI is over 30

Moderate evidence

A meta-analysis of 13 studies found that intentional weight loss in people with obesity and kidney disease reduced proteinuria by about 1.3 g a day and stabilized GFR, and in people with hyperfiltration it brought GFR down toward normal. After bariatric surgery, eGFR decline slows and albuminuria falls by around 30 to 50 percent compared with matched controls over several years.

Avoiding NSAIDs and reviewing supplements

Moderate evidence

Regular NSAID use is associated with about a 20 to 30 percent higher risk of accelerated CKD progression in cohort studies and causes acute kidney injury when combined with dehydration, diuretics and ACE inhibitors or ARBs. Acetaminophen is the usual alternative for pain. Creatine supplements raise serum creatinine (lowering calculated clearance) without harming the kidney, so stop them a week before testing; high-dose vitamin C (over 1 g a day) raises oxalate and kidney stone risk.

Fruit and vegetable intake to correct metabolic acidosis

Preliminary evidence

In small randomized trials in stage 3 and 4 CKD with low bicarbonate, adding 2 to 4 cups of fruit and vegetables a day slowed the decline in eGFR over 3 to 5 years as effectively as oral sodium bicarbonate, with lower blood pressure and body weight as a bonus. The effect is only expected when bicarbonate is below about 22 mmol/L.

Potassium must be monitored; the trials excluded people with potassium above 4.6 mmol/L.

Stopping smoking and controlling blood sugar

Moderate evidence

Smoking roughly doubles the rate of GFR decline in people with diabetes or hypertension in cohort studies, and quitting slows it within a few years. In type 2 diabetes, each 1 percent reduction in A1C is associated with about a 25 to 35 percent lower risk of microvascular complications including kidney disease (UKPDS). Neither reverses established scarring, but both protect the nephrons that remain.

When to see a clinician promptly

  • A creatinine clearance or eGFR below 30 mL/min that is new to you, or any value that has fallen by more than a quarter since your last test: same-week review and likely nephrology referral.
  • Passing very little urine (less than about 400 mL, or roughly 2 cups, in 24 hours), or none at all, especially with vomiting, diarrhea or a recent new medicine or contrast scan: possible acute kidney injury, needs same-day assessment.
  • Breathlessness, chest pain, confusion, severe weakness or palpitations with known low clearance: fluid overload or high potassium can be life-threatening and need emergency care.
  • Visible blood in the urine, foamy urine with new swelling of the legs or face, or a sudden rise in blood pressure, which suggest a glomerular disease that is treated best early.
  • Any clearance below 60 mL/min if you take metformin, a direct oral anticoagulant, lithium, digoxin, gabapentin or regular NSAIDs, so doses can be checked.
  • Persistent nausea, loss of appetite, itching, a metallic taste or muscle twitching with a clearance under 20 mL/min: uremic symptoms that guide the timing of dialysis planning.

Frequently asked questions

What is a normal creatinine clearance?

Roughly 97 to 137 mL/min for adult men and 88 to 128 mL/min for adult women, usually normalized to 1.73 m² of body surface area, with labs differing a little in the exact cut-offs. Clearance falls about 8 mL/min per decade after the 30s, so a healthy 80-year-old often has a value of 55 to 75 with perfectly adequate kidneys. Below 60 for more than three months is chronic kidney disease stage 3 regardless of age, but the risk it carries is much lower in older people without protein in the urine.

How do I calculate creatinine clearance?

The Cockcroft-Gault formula is CrCl = (140 − age) × weight in kilograms ÷ (72 × serum creatinine in mg/dL), then multiplied by 0.85 if you are female. Example: a 60-year-old man weighing 80 kg with a creatinine of 1.0 gives (80 × 80) ÷ 72 = 89 mL/min; a 60-year-old woman of 60 kg with the same creatinine gives (80 × 60) ÷ 72 × 0.85 = 57 mL/min. Online CrCl calculators do exactly this; use actual weight unless you are well above ideal body weight, in which case pharmacists use an adjusted weight.

What is the difference between creatinine clearance and eGFR?

Both estimate how fast your glomeruli filter. eGFR (the CKD-EPI 2021 equation) uses creatinine, age and sex, is indexed to a standard body size and is the number used to diagnose and stage kidney disease. Creatinine clearance by Cockcroft-Gault uses weight and gives an absolute mL/min figure, which is what most drug labels were based on, so it is used for dosing. CrCl typically reads 10 to 20 percent higher than eGFR because the tubules secrete some creatinine, and the two can diverge widely in very heavy, very light, elderly or very muscular people.

Is a creatinine clearance of 60 bad?

Sixty sits exactly at the border of stage 2 and stage 3 kidney disease. If you are over 65, have no albumin in your urine and normal blood pressure, it is often age-related and carries little extra risk; it still means some medicines need lower doses and that NSAIDs should be avoided. If you are 40 with diabetes, or it was 90 two years ago, it is a signal to act on blood pressure, glucose and albuminuria now. Confirm it with a repeat test and a urine albumin-to-creatinine ratio.

Is a 24-hour urine creatinine clearance more accurate than the formula?

Not usually. In theory it measures rather than estimates, but in practice missed voids, timing errors and day-to-day variation of 10 to 15 percent make it no better than a good equation for most people, and guidelines no longer recommend it routinely. It is still useful in people whose body composition breaks the formulas (amputees, bodybuilders, very obese or malnourished patients, pregnancy) and when a kidney donation or chemotherapy dose demands the best possible number, in which case cystatin C or a measured iohexol or iothalamate GFR may be ordered instead.

Why do drug doses use creatinine clearance?

Because the pharmacokinetic studies that set the doses in US drug labels from the 1970s to the 2010s grouped patients by Cockcroft-Gault clearance, so the thresholds such as 'reduce dose below 50 mL/min' or 'avoid below 30' were defined in those units. Newer labels and the FDA's 2020 guidance accept eGFR as well, and for most people the two give the same dosing decision. Discrepancies matter mainly at the extremes of body size and age, and for narrow-margin drugs such as direct oral anticoagulants, where pharmacists still default to Cockcroft-Gault.

What does a low creatinine clearance mean?

It means less blood is being filtered per minute than expected. A modest reduction (60 to 89) in an older adult may be normal aging; a persistent value under 60 is chronic kidney disease, most often from diabetes or high blood pressure; under 30 is advanced disease; under 15 is kidney failure. A sudden fall is more often dehydration, a medication, heart failure or a blockage and is frequently reversible. The trend over time, the urine albumin result and your blood pressure tell you which situation you are in.

Can creatinine clearance improve?

Yes, when the cause is reversible: rehydration, stopping an NSAID or a drug that blocks creatinine secretion, treating an infection or relieving an obstruction can restore clearance within days. Scarring from years of diabetes or hypertension does not reverse, but blood pressure control, SGLT2 inhibitors, glucose control, weight loss, sodium restriction and stopping smoking can slow the decline from several mL/min a year to the 1 mL/min a year of normal aging, which for many people means never reaching kidney failure.

References

  1. Creatinine clearance test. MedlinePlus Medical Encyclopedia, US National Library of Medicine (2023)
  2. Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron (1976)
  3. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney International (2024)
  4. Inker LA, Eneanya ND, Coresh J, et al.. New creatinine- and cystatin C-based equations to estimate GFR without race. New England Journal of Medicine (2021)
  5. Shemesh O, Golbetz H, Kriss JP, Myers BD. Limitations of creatinine as a filtration marker in glomerulopathic patients. Kidney International (1985)
  6. Pharmacokinetics in patients with impaired renal function: study design, data analysis, and impact on dosing. Draft guidance for industry. US Food and Drug Administration (2020)
  7. Estimating glomerular filtration rate. National Kidney Foundation (2024)View source
  8. Hahn D, Hodson EM, Fouque D. Low protein diets for non-diabetic adults with chronic kidney disease. Cochrane Database of Systematic Reviews (2020)
  9. McMahon EJ, Campbell KL, Bauer JD, Mudge DW, Kelly JT. Altered dietary salt intake for people with chronic kidney disease. Cochrane Database of Systematic Reviews (2021)
  10. Navaneethan SD, Yehnert H, Moustarah F, Schreiber MJ, Schauer PR, Beddhu S. Weight loss interventions in chronic kidney disease: a systematic review and meta-analysis. Clinical Journal of the American Society of Nephrology (2009)
  11. Goraya N, Simoni J, Jo CH, Wesson DE. Treatment of metabolic acidosis in patients with stage 3 chronic kidney disease with fruits and vegetables or oral bicarbonate reduces urine angiotensinogen and preserves glomerular filtration rate. Kidney International (2014)
  12. Evaluation of the renal patient. Merck Manual Professional Version (2024)

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This page is educational and is not medical advice or a diagnosis. Lab results have to be interpreted together with your history, symptoms and other results by a clinician who knows you. Do not start or stop a supplement to change a lab value before the cause is known.