Creatinine · high result
High creatinine levels: causes, symptoms and how to lower them
Short answer
Creatinine is a waste product of normal muscle turnover that the kidneys clear from the blood, so a high level means one of two things: the kidneys are filtering less, or there is more muscle (or more creatine) producing it. Most labs call it high above about 1.35 mg/dL in men and 1.04 mg/dL in women. A single mildly high result is often transient — dehydration, a large meat meal, creatine supplements, hard exercise, or a medication such as ibuprofen — and is repeated before anything is concluded. The number that matters is the eGFR calculated from it: an eGFR that stays under 60 for three months defines chronic kidney disease. 'High creatine count' on a blood test is the same question — the lab measures creatinine.
Medically reviewed by Youmna DiStefano, MD · Last reviewed October 2026
When does this result need same-day care?
- A sharp rise in creatinine with very little urine, swelling, breathlessness or confusion — same-day care
- Dark, cola-colored urine with severe muscle pain after intense exercise, heat illness or a fall — possible rhabdomyolysis
What is the normal range for Creatinine?
- Male, age 18+: 0.740 – 1.35 mg/dL
- Female, age 18+: 0.590 – 1.04 mg/dL
Often reflects reduced kidney function, dehydration, or high muscle mass; medications can also raise it.
Full reference table, citations and testing options: Creatinine biomarker page.
What are the common causes of high Creatinine?
- Dehydration — the most common reason for a one-off rise; it usually adds 0.1–0.3 mg/dL and reverses within a day of drinking normally
- Chronic kidney disease, most often from long-standing diabetes or high blood pressure, and less often from glomerular disease or polycystic kidneys
- Acute kidney injury: a severe illness, low blood pressure, contrast dye, or a medication the kidneys did not tolerate — a sharp rise over days
- High muscle mass, creatine supplements, large servings of cooked meat and intense exercise in the days before the draw — more creatinine produced, no kidney problem
- Medications: NSAIDs (ibuprofen, naproxen), ACE inhibitors and ARBs (a small rise of up to about 30% is expected when they are started), trimethoprim and cimetidine (block creatinine secretion without harming the kidney), some antibiotics and chemotherapy drugs
- Urinary obstruction — an enlarged prostate, kidney stones, or a tumor blocking outflow — creatinine rises when both kidneys back up
- Heart failure or liver cirrhosis reducing blood flow to the kidneys
- Rhabdomyolysis — large-scale muscle breakdown after extreme exertion, a crush injury or certain drugs — releases creatinine and a very high CK
- Rarely, a lab artifact: high ketones (diabetic ketoacidosis, strict keto diets) and some cephalosporin antibiotics interfere with the common assay
What symptoms go with high Creatinine?
- Usually none — mildly high creatinine is almost always found on routine blood work, not because of symptoms
- When kidney function is substantially reduced: fatigue, swelling of the ankles or around the eyes, foamy urine, passing less urine or getting up at night to pass it
- Nausea, poor appetite, a metallic taste, itching and muscle cramps as waste builds up
- Trouble concentrating and shortness of breath when the loss of function is advanced
What do clinicians usually check next?
- Repeat well-hydrated, after 48 hours without creatine, heavy exercise or a large meat meal — a normal repeat ends the question for most people
- Read the eGFR reported with it; under 60 is what matters, and the stage depends on how far under and for how long
- Urine albumin-to-creatinine ratio (ACR) and a urinalysis — kidney damage is staged on protein in the urine as much as on eGFR
- Cystatin C–based eGFR when muscle mass, a vegan diet or creatine could be skewing the creatinine estimate
- Potassium, bicarbonate, hemoglobin and phosphorus (on a metabolic panel and CBC) once reduced function is confirmed
- Blood pressure and A1c review, a medication review (NSAIDs are the first thing stopped), and a kidney ultrasound when function is persistently reduced or obstruction is possible
- Nephrology referral when eGFR is under 30, falling quickly, or paired with heavy albuminuria
Follow-up tests available at TestWell: CBC with Differential Test ($17.99), Phosphorus Test ($18.99).
How do you recheck Creatinine?
Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.
| Test or panel | Type | Price | Fasting | Results |
|---|---|---|---|---|
| Basic Metabolic Panel | Test · 8 biomarkers | $17.99 | Yes | 1–3 business days |
Common questions
What is a high creatinine level?
Above the lab's reference range — typically above about 1.35 mg/dL for men and 1.04 mg/dL for women, though ranges vary slightly between labs. The number alone is a poor guide because it depends on muscle mass: a creatinine of 1.3 in a muscular 25-year-old can correspond to a normal eGFR in the 70s, while the same 1.3 in a small 75-year-old woman can mean an eGFR in the 40s. That is why the lab reports eGFR alongside it and why clinicians read the two together.
Is it 'creatine' or 'creatinine' on my blood test?
Creatinine. Creatine is the molecule stored in muscle (and sold as a supplement); creatinine is what it breaks down into, and that breakdown product is what the blood test measures. Searches for 'high creatine count' or 'high creatine levels in blood' are asking about creatinine. Taking creatine supplements does raise creatinine modestly — a well-documented effect that does not mean kidney damage — which is one reason a repeat off the supplement, or a cystatin C, is the usual next step.
What creatinine level is dangerous?
There is no single cutoff, because the same creatinine means different kidney function in different bodies. As a rough guide, a creatinine above about 2 mg/dL in someone who is not unusually muscular usually corresponds to an eGFR under 40 — significantly reduced function that needs a nephrology-level workup — and levels above 4–5 mg/dL, or a rise of more than 0.3 mg/dL within 48 hours, are in acute-kidney-injury or kidney-failure territory. What makes a level urgent is the combination with symptoms (little urine, swelling, breathlessness, confusion) or a fast trajectory, not the number on its own. Decisions about dialysis rest on eGFR, symptoms and electrolytes, not on creatinine alone.
How do you lower creatinine?
By treating whatever is raising it; nothing lowers creatinine directly, and no supplement does. If the cause is transient, the fix is simple: drink normally, pause creatine, stop NSAIDs such as ibuprofen, and avoid heavy exercise and large meat meals for 48 hours before the repeat. If the kidneys are the cause, clinicians focus on what slows the decline — blood pressure control, glucose control in diabetes, stopping nephrotoxic drugs, and kidney-protective medications (ACE inhibitors, ARBs and SGLT2 inhibitors), which can nudge creatinine up slightly even as they protect the kidney. Smoking cessation and moderate rather than very high protein intake help. The test of whether it is working is the eGFR trend over months, not a single value.
Can dehydration cause high creatinine?
Yes, and it is the most common reason for an unexpected mildly high result. Less water in the blood concentrates creatinine and reduces kidney blood flow for a few hours; the rise is usually 0.1–0.3 mg/dL and reverses within a day or two of normal drinking. A fasting draw after a night without fluids, a hot day, a stomach bug or a long run can all do it. That is why a repeat, hydrated, comes before any diagnosis.
Does a high creatinine mean kidney failure?
Not by itself. Chronic kidney disease is defined by an eGFR under 60 (or markers of kidney damage such as protein in the urine) that persists for more than three months — a single high creatinine meets neither test. In otherwise healthy people most mildly high results are transient or reflect muscle mass. Kidney failure is the end of the spectrum, with an eGFR under 15, and it is almost always preceded by years of measurable decline.
How is high creatinine different from a low eGFR?
They are two views of the same thing. eGFR (estimated glomerular filtration rate) is calculated from creatinine together with age and sex, so a high creatinine produces a low eGFR. eGFR is the better number to track because it corrects for the fact that a 25-year-old man and a 75-year-old woman make different amounts of creatinine. A cystatin C–based eGFR removes the muscle-mass problem altogether, which is why it is used to confirm borderline results.
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.